Kaufman County Sheriff's Office via AP

Former Justice of the Peace Eric Williams in a photo provided by the Kaufman County Sheriff's Office.

A former justice of the peace has been charged with capital murder in the deaths of a Texas district attorney, his wife and another prosecutor, Texas authorities said Thursday.

Eric Williams, 46, the former Kaufman County official, is accused of shooting and killing Kaufman County District Attorney Mike McLelland and his wife, Cynthia, and Assistant District Attorney Mark Hasse, NBC 5 of Dallas reported.

"The death penalty is a viable option here," Kaufman County Sheriff David Byrnes told reporters.

The McLellands were found dead in their home March 30. Hasse was gunned down outside the county courthouse Jan. 31.

An arrest warrant affidavit alleges that Williams sent an email to law enforcement confessing to the killings. Williams, who was already in custody on previous charges of making a terroristic threat, was being held on $23 million bond. 

Williams' wife, Kim Lene Williams, also 46, has already been charged with capital murder in connection with all three deaths; authorities said Wednesday that she was being held on $10 million bond.

Kim Williams also confessed to having been involved Tuesday, investigators alleged in an arrest warrant affidavit, which said she gave details that hadn't been made public. She said her husband pulled the trigger, according to police.

Court documents indicated that the Williamses weren't yet being represented by an attorney.

Eric Williams was convicted of stealing computer equipment from a county building last year in a case that was prosecuted by McLelland and Hasse. Williams lost his job and had his law license suspended.

Investigators said both prosecutors "believed that Eric Williams blamed them for his removal from office" and "regularly carried handguns after the Eric Williams jury trial because they believed Eric Williams to be a threat to their personal safety," according to a search warrant the Kaufman County Sheriff's Office filed for the Williamses' home. 

"Justice has been delivered to the citizens of Kaufman and the families of Mark Hasse and Mike and Cynthia McLelland," Diego Rodriguez, the FBI's special agent in charge in Dallas, declared Thursday.

Watch US News crime videos on NBCNews.com

This story was originally published on Thu Apr 18, 2013 3:28 PM EDT

Texas officials theorized Monday that the slayings of a Texas prosecutor and his wife over the weekend and the shooting death of a prosecutor in the same county in January may have been the work of a white supremacist group chillingly called the Aryan Brotherhood of Texas.

Ten alleged members of the gang could face the death penalty if they're convicted of charges — including murder — in a federal racketeering indictment unsealed in November. Texas law enforcement agencies warned shortly after the indictment was opened that there was "credible information" that members were planning to "retaliate."

And the multi-year investigation of the gang had in fact reached into Kaufman County, where District Attorney Mike McLelland and his wife, Cynthia, were shot to death Saturday inside their home, almost exactly two months after Assistant District Attorney Mark Hasse was gunned down in a parking lot.

While Kaufman County Sheriff David Byrnes stressed to reporters Sunday that "there is nothing to indicate" that the two shootings were related, County Judge Bruce Wood — the chief administrator in Kaufman County, akin to chairman of a county commission — told NBC 5 of Dallas on Monday: "This was not just a random act. It seems to me there has to be some connection."

And U.S. Rep. Ted Poe, R-Texas, on Monday said he also believed both shootings could be the work of the Aryan Brotherhood.

"It seems that a scenario may be developing that the district attorney's office was investigating this gang or another gang and they wanted to prevent that investigation, and therefore they resort to violence," Poe told CNN.

Publicly available FBI files describe the Aryan Brotherhood of Texas, or ABT, as a whites-only, men-only organization with thousands of members operating both inside and outside state and federal prisons throughout Texas. The gang was formed in the early 1980s and modeled itself after a California prison gang of the same name, the FBI says.

Mark Potok, a senior fellow at the Southern Poverty Law Center, which tracks hate groups, told MSNBC that ABT was a well-oiled criminal machine and that he wouldn't be surprised if it was behind the killings.

"Like most of these race-based prison gangs, they are fundamentally a criminal enterprise," Potok said. "They are certainly white supremacists, but when push comes to shove, that is quickly set aside in the interests of the criminal enterprise."

Related:

• District attorney, wife shot to death in Texas county where assistant DA was killed, police say
• Texas community in 'shock' over slaying of DA, wife

Almost from the day Hasse was killed, speculation swirled around the county that his death might have been retribution for the racketeering indictments charging 34 alleged ABT members, including four alleged leaders, with multiple murders, kidnappings, assaults and drug operations.

The original Aryan Brotherhood was formed in the notorious maximum-security prison in San Quentin, Calif., in 1964 — as a response to the integration of the prison, according to the Southern Poverty Law Center.

Starting as a race-based protective organization, the AB grew to one of the country's largest prison gangs, with some 15,000 members. Many of the groups operations on the "outside" are direted by leaders who are still incarcerated.

Still unclear is why the gang, or its Texas branch, would target just Kaufman County, which was only one of 24 local, state and federal law enforcement agencies involved in the sprawling investigation. But whether it was involved or not, it's clear that the Aryan Brotherhood of Texas is a nasty bunch.

Members — who identify themselves with tattoos incorporating Nazi-era symbols, often the swastika or the SS lighting bolts — are required to report to outside leaders when they are released from prison, FBI case files record.

The indictment lists alleged crimes — including murder, arson, assault and drug distribution — dating as far back as 1993. Some of the alleged murder victims were ABT members who were killed to enforce discipline, it charges.

"ABT uses extreme violence and threats of violence to maintain internal discipline and retaliate against those believed to be cooperating with law enforcement," Assistant U.S. Attorney General Lanny Breuer said when the indictment was unsealed Nov. 9. 

"Through violence and intimidation, ABT allegedly exerts control over prison populations and neighborhoods and instills fear in those who come in contact with its members," he said.

The operation, as described by the government, is closely similar to that of the 211 Crew, a white-supremacist prison gang in Colorado to which Evan Spencer Ebel was believed to have belonged. Ebel is suspected of having shot and killed Colorado Prisons Director Tom Clements on March 19 before he drove to Texas and died in a shootout with police in Decatur two days later.

Authorities have said they were making "routine inquiries" into whether Ebel may have been involved in the death of Hasse, perhaps through some affiliation between the gangs, but no link between Ebel and ABT has been publicly reported. When the McLellands were killed Saturday, Ebel had been dead nine days.

Kaufman County District Attorney's Office via AFP

Kaufman County District Attorney Mike McLelland.

The murder of two Texas prosecutors is a reminder that officers of courts across the nation continually face threats that can be terrifying but are rarely carried out.

"It comes with the job," said Scott Burns, executive director of the National District Attorneys Association. "We all know that our jobs entail exposing ourselves to threats and risks."

Burns, who was a prosecutor in Utah, said it would be hard to find a member of his group who has not at some point been threatened or menaced.

Yet before Kaufman County Assistant District Attorney Mark Hasse and DA Mike McLelland were gunned down two months apart, the NDAA had counted just 11 revenge slayings of local prosecutors since 1912.

The U.S. Marshals Service keeps tracks of threats against federal prosecutors and judges, and the number has hovered between 1,258 and 1,394 annually for the past five years after doubling between 2003 and 2008.

The National Association of Assistant United States Attorneys said when a threat is lodged, the Marshals Service decides on the response, which can range from a new alarm system for the prosecutor's home to a family escort to 24-hour guard outside the house.

The group's lobbyist, Bruce Moyer, has pushed for more secure parking facilities for federal prosecutors.

"These folks work incredible hours. During a trial it's not unusual for them to be at the office from 10:30 to 11 o'clock at night. Parking is not always in a secure location and they might have to walk several blocks in an urban area unescorted," Moyer said.

He said other federal prosecutors have pushed to be deputized, which would allow them to carry a loaded firearm, but many requests are rejected.

The Marshals Service would not discuss specific security measures but said in a statement that it takes "appropriate steps to provide additional protection when it is warranted."

Personal accounts of unnamed prosecutors who had been threatened were attached to testimony the association submitted to Congress in 2007. They included:

— A prosecutor working a case against a group called Soldiers of the Aryan Culture said the marshals "intercepted a letter which spelled out a directive to killed the 'tall, bald prosecutor who runs a lot, goes to the airport a lot, and drives a silver Honda.'" He already had a home security system after threats during a motorcycle-gang prosecution. Now a closed-circuit TV was placed on a light-pole outside his home and he was deputized.

— A prosecutor whose children were threatened by an inmate said that after the marshals decided he was no longer in danger, he still feared for their lives. "They are now never left alone in our home," he said. His children's bus routes were changed, and he began carrying a gun.

— A drug prosecutor said an inmate tried to hire a hitman and provided him "detailed information about my home, automobiles and family." He was deputized and trained to check his car for a possible bomb, "which I did each day for more than a year."

Kaufman County Sheriff's Department via Reuters

Kaufman County Assistant District Attorney Mark Hasse.

— A prosecutor who said a defendant in a gun case shot at him and another defendant had set his horses and dogs loose on a public roadway. "It is often unavoidably dangerous to be an AUSA and the more time spends in the position, the more danger the position entails," he said.

When he was a county prosecutor, Burns said, there was a defendant who would follow and film him. He would get anonymous phone threats saying, "'You're a dead man.'"

"The worst was when I would show up at a restaurant and find out the cook was someone I had put in prison and I'd already eaten the meal," he said.

But Burns said he didn't dwell on the possibility that someone might strike out because there was little he could do to prevent it beyond responding to a specific threat.

"It's impossible to have any security detail or system in place that would protect prosecutors 24/7," he said. "And the truth is what's happened in Texas is very rare."

He noted that there are 40,000 city, state, county and district prosecutors in the country who handle 10 million felony-level cases a year. Many are threatened; very few are ever attacked.

"Divorce attorneys are more likely to get shot in the head than we are," he said.

The death of Hasse and McLelland will give his membership pause, and they may take the next poison-pen letter or anonymous call more seriously, he said. But in general, he said, they will view threats as an unpleasant part of a job they love.

"You live with it," he said.

Related: Texas community in shock over slaying of DA, wife

David Woo / AP

At a news conference Thursday in Kaufman, Texas, Kaufman County Sheriff David Byrnes bows his head as District Attorney Mike McLelland answers questions about the slaying.

AP

Assistant district attorney Mark Hasse, 57, was shot to death Thursday in Kaufman, Texas.

The National Prosecutor Memorial in Columbia, S.C., lists the names of 11 prosecutors who were murdered in connection to their jobs, a testament to the rarity of such attacks.

In comparison to police officers, who suffer scores of on-duty deaths every year, prosecutors are relatively immune to deadly face-offs with criminals.

"They're not out on the street at 2 a.m. confronting people who are intoxicated, armed and violent," said Scott Burns, executive director of the National District Attorneys Association. "So when a prosecutor is killed, they are almost always premeditated attacks, which kind of raises the level of egregiousness."

The next name to be added to the monument will likely be Mark Hasse, assistant district attorney in Kaufman County, Texas, who was reportedly ambushed by one or two gunmen Thursday morning outside the courthouse where he worked. Hasse was the first DA to be murdered since Sean May, an Adams County, Colo. prosecutor, was shot outside his home in 2008.

The district attorney's association, which maintains the memorial, doesn't keep full historical records involving the killings of prosecutors; its list is almost entirely composed of murders that occurred since 1967, most of them committed by people whom the victims had put in jail or were trying to put in jail.

The only bygone case is William Foster, whose death in an epic gun battle at the Carroll County, Va., courthouse in 1912 has been recreated on stage, in books and through generations of oral retellings.

The list also does not include federal prosecutors. Dennis Boyd, who runs the National Association of Assistant United States Attorneys, said his organization was not aware of any federal prosecutors murdered while on the job or in an attack directly linked to their work. The one possible exception is Thomas Wales, who was shot to death in his Seattle home in 2001, a crime, like May's, that has not been solved.

But the NAAUSA's lawyer, Bruce Moyer, noted that threats against federal prosecutors have been rising in recent years. Citing data provided to him by the Department of Justice, Moyer said reported threats rose from 152 in 2005 to 208 in 2010. He could not say if any of the threats resulted in physical attacks.

Authorities say they do not yet know why Hasse, who prosecuted dozens of criminal cases each year, was shot to death outside Dallas.

But it seems that sometime in the near future, his name will be etched in bronze on that small monument in South Carolina.

Such deaths "strike at the very heart of our justice system," Burns said. "The number-one duty of the government is to protect the people, and these are people who are on the front lines, along with law enforcement officers and court personnel. They go to work every day trying to protect the rest of us and bring us a sense of order via the rule of law."

He added: "While every homicide and murder is egregious, there is something more outrageous about killing someone for being engaged in such an honorable calling."

Also on NBCDFW.com:

• Reward in Hasse's slaying up to $71,000
• Assistant DA Mark Hasse likely targeted in fatal shooting, police say