Sheriffs in Colorado filed a federal lawsuit Friday ahead of the implementation of new state gun laws that broaden background checks and limit the size of ammunition magazines, saying that the bills would be nearly impossible to enforce.

The laws "severely restrict citizens' rights to own, use, manufacture, sell, or transfer firearms and firearms accessories," the sheriffs said in their complaint in the U.S. district court.

"This is a bipartisan effort," said Larimer County Sheriff Justin Smith. "These are Democratic sheriffs and Republican sheriffs who came together."

The National Shooting Sports Foundation, magazine-maker Magpul Industries, and the Colorado State Shooting Association were among other groups that filed suit alongside sheriffs against the laws, which are set to take effect June 1.

Scarred by some of the deadliest incidents of gun violence in American history, including last year's Aurora movie theater shooting and the 1999 shooting at Columbine High School, the state's gun control bills gained national attention as various states and the federal government debated new gun restrictions.

The sheriffs said in the filing that their ability to enforce the laws, particularly the ban on magazines that hold more than 15 rounds, will be constrained by other concerns.

"The Sheriffs have limited resources and limited public funds to spend on investigations," they said in the court documents. "They cannot expend those resources to conduct investigations that would be necessary to monitor compliance with the new magazine restrictions. No documentation has ever been required for the retail or private purchase of magazines, making it a practical impossibility for the Sheriffs to determine whether one of the many magazines already in existence was obtained after the effective date."

The sheriffs also said that Coloradans would find it difficult to comply with expanded background check regulations that would require transfers between individuals to be conducted through a federally licensed firearms dealer. That's because many licensed firearms dealers in the state "are unwilling to conduct the transfer under such conditions," they argued.

Colorado Attorney General John Suthers released a statement on Friday saying that his office would pursue court rulings on the gun legislation “as expeditiously as possible.”

“Colorado citizens, and law-abiding gun owners in particular, deserve such clarification,” Suthers said in the statement.

The state has 64 sheriffs, said Chris Olson, executive director of the County Sheriffs of Colorado. The lawsuit is being brought forth “by individual sheriffs” and his organization is not a party to the suit, he said.

At least one lawman has said that deciding which laws are constitutional should stay out of the hands of Colorado’s sheriffs.

Arapahoe County Sheriff Grayson Robinson, whose county includes the Aurora movie theater where 12 people were killed last year, released a statement in January pushing back against sheriffs who said they would not enforce new gun laws.

“Public safety professionals serving in the executive branch do not have the constitutional authority, responsibility, and in most case, the credentials to determine the constitutionality of any issue,” Robinson said in the statement. “Law enforcement officials should leave it to the courts to decide whether a law is constitutional or not.”

Robinson identified himself as a supporter of Second Amendment rights in the statement, and said he would like to see better mental health services and stricter penalties for people who commit gun crimes.

Related:

• Colorado Gov. Hickenlooper signs landmark gun-control bills
• Colorado sheriff blasts colleagues over refusal to enforce gun laws
• After Newtown, states slow to embrace new gun laws

By Tracy Connor, Staff Writer, NBC News

Federal law requires anyone served with an order of protection to give up their guns, but it's rarely enforced at the state level, leaving domestic violence victims in jeopardy.

One community in California, though, is using a federal grant to tackle the problem -- with promising results, as a report by NBC News' "Rock Center with Brian Williams" found.

San Mateo County Deputy Sheriff John Kovach and his partner head a team that tracks down and confiscates these weapons one by one. Last year, his department collected 324 firearms and for the third year didn't have a single gun-related domestic violence homicide.

"We have shotguns, rifles, pretty much any kinda gun you can imagine," Kovach said as he displayed the contents of his gun vault.

"Right here we have a submachine gun that was actually purchased illegally in Nevada and brought into the State of California. And this was recovered during one of our investigations of a restraining order."

When someone in his county takes out an order of protection, Kovach interviews them to find out what kind of guns the other party might have. Then he goes to the home to serve the order and take the weapons.

Sometimes the owner says they don't have the weapons any longer; sometimes they say they're at a relative's home, which means another stop for Kovach and his partner.

The sleuthing and legwork is worth it, he said.

"I've worked in a lot of different areas of law enforcement," Kovach said. "They are all satisfying, but nothing like this."

He noted that responding to a domestic violence incident is among the most perilous calls for a police officer. Getting guns out of the hands of those with restraining orders means other cops -- along with civilians -- are safe, he said.

In Spokane, Wash., mother of two Stephanie Holten learned how ineffective an order of protection can be if the other person is still armed.

After she told her ex-husband she was seeing someone else, he threatened her, she said.

"He said to my face that he would come over to my house and put a gun in my mouth and pull the trigger, that he would blow my head off," she said.

She filed a police report and obtained an order of protection. Police served her ex with the order, but no one took his gun. Nine hours later, he was at Holten's door with the weapon.

"He starts yelling at me, 'I was served a protection order today and I'm going to kill you. I'm going to shoot you,'" Holten recalled.

"I'm on my knees by the living room couch and he's standing over me. And I am looking at this gun barrel."

Secretly Holten used her cell phone to call 911, and police rescued her. Her ex-husband is in prison now.

Kelly Starr of the Washington State Coalition Against Domestic Violence said the episode could easily have had a more tragic ending.

"When there is a gun around is when we see domestic violence turn to murder," she said. "What we know is that domestic violence victims are five times more likely to be killed if there's a gun around."

Statistics like that are why Kovach believes he is making a difference.

"I know I am saving lives," he said.

Related links:

Son of a transgender author: 'I live in a normal family'

More from Rock Center with Brian Williams

Johnny Hanson / AP

Barry Bailey and his wife Judy, of DeRidder, La., walk out hand-in-hand, after having their 1873 Winchester shotgun appraised at the NRA's Antiques Guns and Gold Showcase during the National Rifle Association's 142 Annual Meetings and Exhibits at the George R. Brown Convention Center in Houston. The 2013 NRA Annual Meetings and Exhibits runs from Friday through Sunday, with more than 70,000 people expected to attend.

HOUSTON – A thousand miles couldn’t keep them away.

Bob Kittredge, 73, and his wife drove from Port St. Lucie, Fla., this week to attend the National Rifle Association’s annual convention. They are just two of the more than 70,000 people expected at the event, which opens Friday and runs through Sunday.

“We meet a lot of people who think the same way we do,” Kittredge said.

It will be a nine-acre gun show in the middle of a national gun fight.

About 550 exhibitors have packed the sprawling George R. Brown Convention Center in downtown Houston.

"NRA members vote and their friends vote,” said Drew Kelley, who said he’s been an NRA member for most of his life. “That is what's driving all this."

Kelley works for ProMag Industries, a firearm magazine manufacturer in the Los Angeles area that’s been in business for about 35 years and employs about 150 people.

Kelley said he values the Second Amendment – and that recent attempts at tighter gun control measures are misguided.

“The whole idea was to keep people who should not have guns from acquiring them,” he said. “But the people who they're talking about don't go through the normal commercial processes anyway.”

'Stand and Fight'

 After the mass shootings in Aurora, Colo., and Newtown, Conn., the NRA’s opponents seemed to have momentum. But two weeks ago, a bipartisan compromise on expanded background checks for commercial gun sales was shot down in the Senate.

“We don't mistake battles for wars,” outgoing NRA president David Keene told NBC News. “It was a victory in a battle, but the war continues.”

Keene’s two-year term concludes at the convention. Starting Monday, Keene will be replaced as president by Alabama attorney Jim Porter, although Executive Vice President Wayne LaPierre will continue to be the organization’s main spokesman.

In his letter to convention attendees, LaPierre writes: “For months, our enemies have laid siege to the rights we cherish…But we are proving to be stronger than ever.”

This year’s convention slogan: “Stand and Fight.”

“My concern as an NRA member is that any legislation needs to be targeted towards criminals and not law-abiding people,” said Bill Dermody, who works for Savage Arms, the Massachusetts-based firearm manufacturer that is one of the largest in the country and one of the convention’s 550 exhibitors.

On Friday afternoon, scheduled speakers include Sarah Palin, Texas Gov. Rick Perry, Texas Sen. Ted Cruz, Louisiana Gov. Bobby Jindal and former Pennsylvania Sen. Rick Santorum.

The opposition

 Outside the convention hall, several gun control advocates are planning to protest. At least one relative of a Newtown victim will attend. Another group plans to set up across the street and read 4,000 names of victims of gun violence.

The NRA’s opponents are launching a coordinated effort ahead of the 2014 midterm elections. The groups claim they finally have the financial clout to challenge the NRA thanks to Super PACs backed by New York Mayor Michael Bloomberg and former Arizona congresswoman Gabrielle Giffords.

"We're simply losing too many loved ones to this epidemic and it's time for change," said Ladd Everitt, the spokesman for the Coalition to Stop Gun Violence. “And if people won't do the right thing, then we are going to work tirelessly to make sure their political careers come to an end.”

Gun control advocates argue that the NRA’s leadership cares more about the gun industry – and profit – than the rights of gun owners.

“I think the NRA leadership is wildly out of step with their own members on the issue of expanding background checks,” Everitt said.

Philip Kamrass / AP

Gun enthusiasts gather during the annual New York State Arms Collectors Association Albany Gun Show in this Jan. 26, 2013, photo.

Key measures of New York's new gun law are set to kick in, with owners of guns now classified as assault weapons required to register the firearms and new limits on the number of bullets allowed in magazines.

As the new provisions take effect today, New York's affiliate of the National Rifle Association said it plans to head to court to seek an immediate halt to the magazine limit.

Gov. Andrew Cuomo calls those and other provisions in the state's new gun law common sense while dismissing criticisms he says come from "extreme fringe conservatives" who claim the government has no right to regulate guns.

"Yes, they are against it, but they are the extremists and the extremists shouldn't win, especially on this issue when it is so important to the majority," Cuomo said in a radio interview last week. "In politics, we have to be willing to take on the extremists, otherwise you will see paralysis."

New York's new gun restrictions, the first in the nation passed following December's massacre at a Connecticut elementary school, limit state gun owners to no more than seven bullets in magazines, except at competitions or firing ranges.

The new regulations in New York commence as the U.S. Senate prepares to debate expanded gun legislation and weeks after Connecticut joined Colorado in signing into law tougher new gun restrictions.

The New York State Rifle & Pistol Association, the state's NRA affiliate, has a pending federal lawsuit against the new provisions. It plans to ask a judge Monday for an immediate halt to the magazine limit. The new registrations, required over the next year, will be the group's focus later.

The law violates the constitutional rights of law-abiding citizens "to keep commonly possessed firearms" at home for self-defense and for other lawful purposes, the New York State Rifle & Pistol Association said in court papers. It is advising members to obey the law in the meantime.

"We are lawful and legal citizens of New York state and we always obey the law," association President Tom King said. "It's as simple as that."

State Police planned to post forms on their website for registration starting Monday. Owners of those guns, now banned from in-state sales, are required within a year to register them. Alternatively, they can legally sell them to a licensed dealer or out of state by next Jan. 15.

Rich Davenport, recording secretary of the Erie County Federation of Sportsmen's Clubs, said their nearly 11,000 members are united in opposition to the law, which he considers a hasty, illogical and emotional response to the Newtown, Conn., school shooting. He also questioned likely compliance with the registration requirement.

"I'm guessing it'll be pretty low," said Davenport, a longtime hunter. He said that even though he's not personally affected by the registration provision, "I'm offended as an American."

The toughest part of the new statute — banning in-state sales of those guns newly classified as "assault weapons" — immediately took effect Jan. 15. The new classification related to a single military-style feature, such as a pistol grip on semi-automatic rifles with detachable magazines. Other listed features include a folding or thumbhole stock, bayonet mount, flash suppressor, or second protruding grip held by the non-trigger hand.

It requires owners to register an estimated 1 million guns previously not classified as assault weapons by April 15, 2014, though law enforcement officials acknowledge they don't know exactly how many such guns New Yorkers have.

The assault weapon definition also applies to some shotguns and handguns. They include shotguns that are semi-automatic, or self-loading, and have another feature, such as a folding stock, a second handgrip held by the non-shooting hand or the ability to accept a detachable magazine.

Also covered are semi-automatic pistols that can take detachable magazines and have another feature, such as a folding or thumbhole stock, a second handgrip and a threaded barrel that can accept a silencer.

Many county boards in New York have passed resolutions urging at least partial repeal of the law while warning that new registration requirements would be a costly burden on them.

Herkimer County Clerk Sylvia Rowan said Thursday she had received no registration forms for those guns. "There's a lot of confusion on this," she said.

Rowan noted that she had received few formal requests filed from the holders of the county's 12,000 pistol permits to exempt their information from public disclosure, something else authorized under the new law.

Passed Jan. 15, a month after the school shooting in Newtown, Conn., the statute originally banned magazines with more than seven bullets effective April 15. Connecticut officials said that shooter Adam Lanza used a semi-automatic Bushmaster AR-15 and five 30-round magazines to kill 20 children and six adults in minutes.

However, acknowledging that manufacturers don't make seven-bullet magazines, the Cuomo administration and New York lawmakers amended their law on March 29, keeping 10-bullet magazines legal but generally illegal to load them with more than seven bullets.

The new Colorado bill, signed into law last month, bans ammunition magazines that hold more than 15 rounds.

Related:

Supreme Court passes on gun case

Gun group endorses background checks

Conservative group: Stop gun bill

Joe Raedle / Getty Images, file

As the U.S. Senate takes up gun legislation in Washington, DC , Mike Acevedo puts a weapon on display at the National Armory gun store on April 11, 2013 in Pompano Beach, Florida.

A Senate proposal to expand criminal background checks to people who buy firearms at gun shows and online would increase sales at traditional gun stores, many retailers agree — and perhaps even hand licensed dealers a “sweetheart” boon that amounts to “an Obama tax,” according to one industry leader.

The bipartisan plan to broaden background checks — fueled by anger from the mass shooting in Newtown, Conn., as well as the gun-control push from the Obama Administration — would “bring a lot of money” to the bricks-and-mortar gun sellers, predicts Andrew Molchan, director of the National Association of Federally Licensed Firearms Dealers, which has about 1,000 members.

“It's kind of like a sweetheart union deal" that would be realized by gun store owners Molchan said. “Most FFL holders already charge for [private gun] transfers, and when it becomes a law they'll charge more." 

If instant criminal background investigations were to be federally mandated for all guns sold via the Internet or at gun shows, that task would fall to retailers. Some gun-store owners argue such a change would increase their workload and their legal risk, thus dampening the positive impact of having more firearms owners visit their establishments. But Molchan contends the tightened rules will ultimately deepen the revenue stream for licensed dealers.

“It's an ‘Obama Tax,’ with all of the money going to the FFL holders: gun stores, pawn shops, sporting goods stores, hardware stores,” he added. “The bottom line for the real world is that a year from now [if the law passes] there will be more gun stores.”

Other firearms sellers and industry analysts don’t envision gun-shop cash registers humming at quite the rapid pace that Molchan forecasts should Congress vote to pass the bill, but there seems to be consensus that profits at those locations will rise to some degree. 

'Treacherous direction'
An earlier plan pitched by the White House to require universal background checks — to cover all private firearms sales — would have generated an even larger payday for gun shops through far heavier foot traffic and even fatter bumps in side sales of ammunition and cleaning supplies, said Garen Wintemute, a firearms researcher and a professor at the University of California, Davis, where he also serves director of the Violence Prevention Research Program.

“The current [Senate] proposal falls well short of a comprehensive background-check policy [so] the benefit to retailers will be smaller than it otherwise will be,” Wintemute said.

Advocates for tougher gun laws have long contended that 30 to 40 percent of criminal firearm acquisitions are made from family and friends and, thus, done off the books, without background checks. However, many gun owners and sellers argue that number was plucked from 1990s research and that actual portion is probably closer to 10 to 13 percent. 

Gun shows typically include many tables occupied by licensed sellers (including retailers) who are required by law to conduct background checks even at those transitional venues. That means the proposed background-check extension would only affect “individuals who are selling their personal collections” at such events, and “that’s not a big factor,” said Larry Hyatt owner of Hyatt Gun Shop in Charlotte, N.C.

“One reason a lot of people want to buy a gun at a gun show from another individual is because they don’t want the government to know. They’re not buying because they are criminals or have criminal intent. They just want to be invisible,” Hyatt said. “That’s a huge issue in the country."

Broadening background checks to include gun shows and Internet transactions will have “a pretty small” impact on stores like Hyatt’s, he said. “There are still going to be people who wouldn’t buy from us anyway because they wouldn’t want a record [of the purchase]. It’s not anything evil. It’s brought about by some of this fear of government and fear of future gun laws. Because people see an inevitable descent [toward gun bans]. They see an overall treacherous direction.”

A mother who lost her 6-year-old son in the shooting at Sandy Hook Elementary School made an emotional plea for national gun-control legislation in an address from the White House.

Francine Wheeler made her appeal in lieu of the president’s weekly address. Her appearance is the only time President Obama has handed the address to anyone other than Vice President Joe Biden since the two first took office. Wheeler was joined by her husband David.

“I have hear people say that the tidal wave of anguish our country felt on 12/14 has receded, but not for us,” Wheeler said. “To us it feels as if it happened just yesterday, and in the four months since we lost our loved ones, thousands of other Americans have died at the end of a gun.”

The address, taped Friday, comes as several Sandy Hook families have mounted an aggressive effort to get a gun-control bill passed by Congress. Wheeler and her husband wrote the remarks after they were approached, the White House said.

“We have to convince the Senate to come together and pass common sense gun responsibility reforms that will make our communities safer and prevent more tragedies like the one we never thought would happen to us,” Wheeler said.

Jessica Hill / AP file

Francine Wheeler, mother of Sandy Hook Elementary School shooting victim Benjamin Wheeler, cries as she listens to Vice President Joe Biden speak during a gun violence conference in Danbury, Conn., Thursday, Feb. 21, 2013.

Family members of the Newtown victims were present on Capitol Hill Thursday when Senators voted 68-31 to move forward with the process of debating a gun bill that several Republican lawmakers had threatened to filibuster. Several Republican senators have said that the presence of Newtown families helped contribute to the unexpectedly overwhelming vote to move forward with the bill.

Among the more than a dozen relatives in the gallery was Jillian Soto, whose sister was killed at Sandy Hook.

“The tears that we had weren’t tears of joy, but tears of remembering this is happening,” Soto told NBC News shortly after the vote. “We’re here because of what happened to us.”

During her remarks, Wheeler and her husband wore green pins to commemorate the 20 schoolchildren, including their son, and six adults who died in the December shooting. The Wheelers’ older son Nate, a 4th grader at Sandy Hook, survived the shooting.

“Sometimes I close my eyes and all I can remember is that awful day waiting at the Sandy Hook volunteer firehouse for the boy who would never come home – the same firehouse that was home to Ben’s Tiger Scout Den 6,” said Wheeler, choking back tears. “But other times I feel Ben’s presence filling me with courage for what I have to do for him and all the others taken from us so violently and too soon.”

The Associated Press contributed to this report.

Related:

• Newtown passion moves Senate vote on guns
• Newtown Victim's mom to give Obama's weekly address
• Newtown families lobby for gun control

Two critical senators with “A” ratings from the National Rifle Association proposed a deal Wednesday that would expand background checks on firearms sales, which are currently required on purchases from federally licensed dealers. The compromise proposal put forward by Senators Joe Manchin and Pat Toomey would mandate them for sales at gun shows and on the Internet as well, yet make an allowance for transfers between family members.

More than 167 million checks were made through the FBI's system between 1998 and early 2013, but the process remains obscure to many Americans. What are background checks, and why has it taken so long for lawmakers to piece together a deal on a measure polls say is overwhelmingly favored by American voters? Here’s a primer:

How do background checks work now?

The Brady Handgun Violence Prevention Act of 1993 established the National Instant Criminal Background Check System (NICS), which allows the seller to check a buyer’s eligibility with a search that usually takes less than a minute. The system was fully launched in 1998. Before selling a gun, the gun store worker calls in to the FBI or other designated law enforcement agency to run a check against the system’s records. If the prospective buyer’s record doesn’t raise a red flag – possible triggers include a person having been adjudicated as mentally ill or being sought by law enforcement – the sale is cleared to go through.

What kinds of gun purchases don’t require background checks under current law?

That depends on where you live. In the wake of the Newtown school shooting, President Obama asked for a federal law that would require universal background checks, including at gun shows. Right now, only California, Colorado, Illinois, New York, Oregon, and Rhode Island require background checks at gun shows, according to the Coalition to Stop Gun Violence. But most states have looser restrictions. While local laws can vary widely, 33 states do not have a law addressing what is commonly referred to as the “gun show loophole.” Similarly, regulations on sales between private parties or transfers between family members can be very different from state to state, where they exist at all.

Is the background-check system foolproof?

Critics of the current background check system point to gaping holes in the ways states submit records to the NICS. While 44 states have individual laws regulating the sale of firearms to the mentally ill, for example, far fewer states submit the names of prohibited mentally ill individuals to the national database. Just seven states account for 98 percent of the names prohibited for mental illness, according to Mayors Against Illegal Guns, meaning most states are in there barely, if at all. In one oft-cited example, Virginia Tech shooter Seung-Hui Cho passed a background check before obtaining a gun and killing 32 people, despite having been declared mentally ill two years before. States are responsible for compiling mental health records from courts, hospitals, and other sources to submit to NICS, but they are not legally required to do so.

Does the public support broader background checks?

The vast majority of American voters do. Eighty-five percent of Americans said they support background checks at gun shows and for private sales in a Pew Research Center poll released earlier this year. Other polls have found even wider support for broadening checks, with 92 percent of respondents to a February survey by Quinnipiac University saying they favored them on every single gun sale. That number dropped to 91 percent among gun-owning households.

Given this level of support, why aren’t universal background checks already law?

That’s a harder question to answer, as the issue becomes bitterly political. Momentum on Capitol Hill toward a bill requiring comprehensive background checks has been slow to gain traction. Republican Senators Ted Cruz, Rand Paul, and Mike Lee said that they would filibuster debate on new gun legislation, but that idea lost steam on Tuesday as other Republican lawmakers including Sen. John McCain said they would not support a filibuster. The NRA released a statement on Wednesday after the Manchin-Toomey compromise was announced saying that expanding background checks “will not prevent the next shooting, will not solve violent crime and will not keep our kids safe in schools.” Other opponents of expanded background checks have argued that they would require a national registry of gun owners, something the White House has denied.

Are background checks effective?

The numbers show that background checks do keep guns out of the hands of at least some people who are not supposed to have them. Nearly 1.8 million applications for firearm transfers or permits were denied between the passage of the law in March 1994 and December 2008, according to the Bureau of Justice Statistics. The FBI and state law enforcement denied firearm purchases to 153,000 people in 2010 alone, the most recent year for which data is available.

Jim Lo Scalzo / EPA file

Shoppers examine handguns on display for sale at The Nation's Gun Show held in the Dulles Expo Center in Chantilly, Virginia, USA, 28 July 2012.

Related:

• 'The monster want out:' Mentally ill killer amassed huge arsenal, police say
• Support soars for tougher gun laws, surveys show
• Gun instructor could get permit back after threatening to 'start killing people'

The daughter of Sandy Hook Elementary's slain principal wants to talk to all the senators who threatened to filibuster gun-control legislation, but only one has answered her calls and tweets.

Erica Lafferty's Twitter feed drew lots of attention when she called out the 14 politicians Tuesday, tweeting poignant messages and photos about her mother, Dawn Hochsprung, to their official accounts.

Connecticut Gov. Dannel Malloy started retweeting her, and she got hundreds of replies, retweets and mentions from strangers around the country.

So far, only one of the senators -- Ted Cruz of Texas -- has reached out to Lafferty, 27.

"We agreed to disagree," Lafferty said Wednesday. "At least he called me back."

Cruz's office did not provide details about the "personal" chat.

"He is glad they had the chance to speak and it was a respectful conversation," said spokeswoman Catherine Frazier.

Even as senators announced a possible deal on background checks, Lafferty said she still wants to hear from the other 13 on why they would threaten to block debate and voting on legislation sparked by the Newtown, Conn., massacre.

"What are they scared of? My mother wasn't scared in the halls at Sandy Hook," she said. Lafferty would like to see legislation passed that includes universal background checks and an assault weapons ban.

Most of the Senate offices did not immediately respond to an email inquiry about Lafferty's efforts. A spokesman for Sen. Mike Lee of Utah said he couldn't find a record of a call but was willing to "work it out" with her. An aide to Sen. Jerry Moran of Kansas said they were working to arrange a meeting.

Lafferty, meanwhile, was taking her campaign from Twitter to the airwaves, appearing on several TV news shows.

"They're not going to shut me up," she said. "I'm loud. I'm opinionated. If people want to hate me because I'm trying to protect their children, let them hate me."

Related:

Senators announce gun deal, raising hope of passage

Biden: Filibuster threat on guns 'embarrassing' to the nation

This story was originally published on Wed Apr 10, 2013 2:10 PM EDT

Four-year-old boys in different states were involved in two separate shooting incidents in the last four days, with tragic results.

On Saturday, a Tennessee boy discharged a pistol at a sheriff's deputy's wife, killing her instantly. On Monday, a New Jersey toddler killed a 6-year-old neighbor after a rifle was fired at his head.

The Tennessee incident occurred during a family cookout at the home of Josephine and Daniel Fanning. He's a sheriff's deputy in Wilson County.

Deputy Fanning, 51, was in his bedroom showing his collection of weapons to a relative around 7:00 p.m. Saturday, when Josephine, 48, and the 4-year-old came into the room. The young boy grabbed a loaded handgun sitting on the bed and fired it once, striking and killing the deputy’s wife, according to Tennessee Bureau of Investigations spokeswoman Kristin Helm. She was pronounced dead at the scene.

The incident appears to be an accident and no one has been charged, but the investigation is still open, according to Helm.

“It’s a sad, sad set of circumstances,” Sheriff Robert Bryan told NBC affiliate WSMV in Nashville. "Nobody is immune to this. Nobody. It doesn't matter if you are a law enforcement officer. These things can happen in second."

The 4-year-old is a relative of the deputy and his late wife, WSMV reported. The weapon used by the 4-year-old boy was not Deputy Fanning’s service weapon.

Another tragic incident took place in New Jersey on Monday evening, when a 4-year-old boy accidentally shot a 6-year-old neighbor with a rifle he found in his parents’ home.

Police said the two boys were playing with a .22-caliber rifle outside the 4-year-old’s home in Toms River, N.J., when around 7:00 p.m. the gun discharged and struck the 6-year-old in the head, NBCNewYork.com reported.

The 4-year-old's parents reportedly heard the shot and called 911.

According to NBCNewYork.com, the 6-year-old was taken to Jersey Shore Medical Center, where he later died. An investigation is ongoing.

The sale of military-style weapons in Maryland has skyrocketed because of the concern they'll will be banned once the strict gun control bill passed by the Maryland General Assembly on Thursday goes into effect.

At Engage Armament in Rockville, there are only a few assault weapons left because so many have been sold in anticipation of gun restrictions.

Ammunition has gone up in price -- that is, if you can even find bullets in stock.

"Everything's been bought up and we've had ammunition that came right off the trucks," said A.J. Wynne, an employee at Engage Armament. "They'd say, 'What is that?' I'd say, '9 mm.' [They'd say,] 'I'll take it.' Right before we're even done booking guns in, it's already sold."

Geogre Heffner was in the store Friday, purchasing a handgun that he had ordered months ago.

"When I came here two months ago, there was nothing to be had," he said. "The store was completely empty. I thought someone had come in and robbed it. Nothing on the shelves hardly at all.... Completely sold out."

The Brady Campaign to Prevent Gun Violence issued a statement saying: "We fully support Governor O'Malley's comprehensive legislation passed by the Maryland General Assembly. His leadership in the area of gun licensing, restricting access to military-style assault weapons and gun magazines will save lives."

In Prince George's County, youth violence is a growing concern. Seven teens have been shot and killed in the county during this school year.

"As... a person that has kids and [is] concerned about youth violence, I think [gun control is] something that would be a great asset to my kids that are growing up now, in today's society," said Prince George's County resident Darnell Johnson.

But opinion is divided whether gun control is the answer.

"Personally, I think the problem is a little deeper," said Prince George's County resident Dexter Taylor."We need to catch some of these younger people... and try to keep them from going in that direction in the first place."

With a green and white ribbon to commemorate the victims of one of the worst school shootings in American history pinned to his lapel, Connecticut Gov. Dan Malloy signed a broad new package of gun laws Thursday in the state where 20 children and 6 educators were slain nearly four months ago.

Connecticut is the third state, following Colorado and New York, to pass sweeping new gun legislation after the December school shooting.

“This is a profoundly emotional day, I think, for everyone in this room and everyone watching what is transpiring today in the state of Connecticut,” Malloy said before signing the bill. “We have come together in a new way that relatively few places in our nation have demonstrated an ability to do.”

Lawmakers had worked to forge a bipartisan consensus around the bill. The final package limited the size of gun magazines to 10 rounds, expanded the state's existing assault weapons ban, and required universal background checks on all gun sales in the state.

The bill passed by bipartisan majorities in both the Senate and the House.

“I’ve been amazed at the strength of the families since the day of Newtown,” Lt. Gov. Nancy Wyman said at the Thursday ceremony.

State Sen. John McKinney, a Republican who represents Newtown, said on Wednesday that the bill was an imperfect but necessary step in the wake of the Sandy Hook tragedy.

"The message we can send if those outside the walls of Connecticut are listening is encourage them to do the same, encourage our elected officials in Washington to put aside the politics and see if they can find some common ground," McKinney said Wednesday.

The Connecticut Citizens Defense League, a group that opposes gun control, denounced the new legislation in a post on its blog, saying that when the bill took effect Connecticut would have “the most unconstitutional gun laws in the entire country.”

Adam Lanza fired 154 rounds in fewer than 300 seconds after he entered the Newtown school armed with a Bushmaster .223 rifled and several 30-round magazines, according to investigators.

The shooting provoked a national outcry for tighter gun controls, but so far, with the exception of Colorado, New York and Connecticut, few states have made sweeping changes.

And a handful of states, such as Arkansas, Tennessee, and Kentucky, have gone the other direction, passing laws that would expand who can carry a gun and where.

President Obama pushed for a new federal law requiring more comprehensive background checks in a speech in Colorado on Wednesday. Obama said there “doesn’t have to be a conflict” between new gun laws and respect for gun rights.

Senator Chris Murphy, a Democrat, said the Connecticut bill provides an example to his fellow federal lawmakers on how to pass “tough, common sense gun laws.”

“The people of our state know that it takes bold, courageous action like this to help prevent the next tragic shooting,” Murphy said in a statement.

New York Gov. Andrew Cuomo, who led an aggressive January charge to tighten his state’s already strict laws, congratulated Connecticut lawmakers on Thursday “for taking bold new action to protect the people of their state.”

The mother of one of the school children killed at Sandy Hook Elementary School thanked Gov. Malloy at the Thursday signing. Nicole Hockley’s son Dylan was among the young students who died on December 14.

“While I am grateful for the progress being made, I wish more than anything that I were just back at home waiting till it was time for both Dylan and Jake to come home from school,” Hockley said.

Related:

• Connecticut lawmakers approve 'toughest' gun laws in US
• 'Insane' crowds as customers flood Connecticut gun stores before vote
• Connecticut lawmakers reach deal on 'most comprehensive' gun limits in US