He was a "shut-in," a young man with a twisted murder obsession holed up in a suburban house with guns, Samurai swords and a mother who searched self-help books for solutions to his social disorder.

That's the picture that emerged Thursday of Adam Lanza as search warrants carried out after his Dec. 14 massacre at Sandy Hook Elementary School were made public.

The documents provide no clear motive for the two-part rampage that left 20 children, six school staffers, Lanza's mother Nancy and the gunman dead, but they hint at the activities that consumed his days behind dark-green shutters on Yogananda St. in Newtown, Conn.

One piece of paper seized from the home is particularly chilling in hindsight: a 2008 New York Times clipping about a shooting at Northern Illinois University, where a gunman murdered five people, wounded another 21 and then killed himself.

Although it's not spelled out in the warrants, a law-enforcement source told NBC News that police also found a spreadsheet that Lanza toiled over, cataloging the details of mass murders through the years.

Police also discovered Lanza's journals, though the warrants don't divulge if they contained any clues about why the 20-year-old slaughtered defenseless first-graders or how long he had planned the shooting spree.

There was a large assortment of computer equipment, including a custom-built desktop unit — not surprising since Lanza reportedly earned an A in computers as a 16-year-old freshman at Western Connecticut State University and worked for a time at a computer store.

Don Emmert / AFP - Getty Images file

Search warrants executed at the Lanza home in Newtown, Conn., detailed the weaponry found inside, along with books about autism and a newspaper clipping about a 2008 mass shooting.

More notable were missing and damaged hard drives, which law-enforcement experts saw as a sign that Lanza didn't want police to examine his computing history after he joined the nation's growing roster of mass killers.

The electronics seized included a Xbox system, and the warrants quoted an anonymous tipster who told the FBI that Lanza was "an avid gamer who plays Call of Duty."

Full documents: Read the Sandy Hook search warrants

Most startling was the array of weapons found at the Lanza home and at the school: a half-dozen handguns and rifles, a BB gun, a starter pistol, hundreds of rounds of ammunition scattered about, high-capacity magazines, three Samurai swords, a bayonet and smaller knives in sheaths.

"It's a stunning amount of ammunition and weaponry," said Mary Ellen O'Toole, a former FBI profiler.

"If the family dynamic is gun-oriented, that's fine. But how do they treat it? Are their weapons locked up? Is the ammunition kept in the same place? These documents tell us this is not the case. You've got this stuff laying all around and it's not stored properly."

The warrants also reveal that bullets were kept in a Planters nut canister and plastic baggies, in a bedroom gun safe, on closet shelves, in a shoe box, a duffel bag, and a filing cabinet drawer.

Family friends and acquaintances have said that Nancy Lanza, who grew up in rural New Hampshire, saw recreational shooting as something she could do to bond with Adam and his older brother, Ryan.

New details about Sandy Hook massacre gunman Adam Lanza were revealed in search warrants released Thursday.

A holiday card found in the house underscores that connection: it contained a check that Nancy wrote to Adam for the purchase of a firearm, according to the warrants.

Mother and son both had documents described as National Rifle Association certificates, though it was unclear what that signified, along with files of gun-related receipts, manuals and other paperwork.

Had the guns and ammunition been kept in a safe place and had Adam Lanza been a well-adjusted person with friends and outside interests, the arsenal might not have raised any eyebrows, O'Toole said.

But Lanza didn't fit that description.

The FBI tipster told agents the suspect "rarely leaves his home and considers him to be a shut-in," according to the warrants.

An extensive profile of the shooter in the Hartford Courant last month chronicled how Lanza cut himself off from others in the last two years of his life — following his parents' divorce and an abrupt end to his education, which had been a patchwork quilt of mainstream and special-education classes and home-schooling.

The FBI's source said school had been Lanza's "life" and that he once attended Sandy Hook. After moving from New Hampshire to Newtown, Lanza entered the first grade there. A report card from Sandy Hook was found in the home.

Over the next decade, Lanza was shuttled in and out of classrooms by his mother, who believed he had sensory integration disorder and needed independent study at home, the Courant reported.

Lanza hated to be touched, had few friends and was easily freaked out by changes in routine, the newspaper said. In middle school, he was diagnosed with Asperger's syndrome, a condition on the autism spectrum marked by social awkwardness and obsessive interests.

Phil Simpson via Reuters file

A former FBI profiler says Adam Lanza's mother, Nancy, seen here on a 2008 cruise, may not have acted on warning signs that her son could turn violent.

Proof that Nancy Lanza was still looking for insight into her son's behavior years after that diagnosis could be found on her home's bookshelves. Among the titles seized by police were a primer on Asperger's and another on autistic savants.

A third book, "Train Your Brain to Get Happy," had pages tabbed off, though it was unknown if mother or son had been looking for the "joy, optimism and serenity" promised in the subtitle.

Those feelings appeared to be elusive at the two-story yellow Colonial, where investigators found three gruesome pictures of a blood-spattered body under plastic. The origin of the photos was not specified.

O'Toole said the warrants reveal there was no shortage of warning signs for Nancy Lanza that her younger son was headed down a dark path.

"But it takes a big step for a lot of people who love their children to go from, 'I think i have a problem' to 'I think this person could commit homicide,'" she said. "It's not unusual for people to ignore behavior, explain it away or to normalize it or to rationalize it."

Not unusual — but in this case, fateful.

Among the other items ticked off in the warrants were two bloody sheets, apparently from the bed where Nancy Lanza was killed with a .22-caliber round to the forehead while sleeping, just before her son loaded her Honda Civil with handguns, rifles and bullets and, police say, went hunting for innocent children.

NBC News' Michael Isikoff contributed to this report

Related:

Invoking Newtown, Obama presses Congress on guns

Sandy Hook shooter fired 155 bullets in 5 minutes, documents show

Guns, ammo, Samurai swords: Adam Lanza's arsenal

Pool/The News-Herald via AP

T.J. Lane, wearing a "KILLER" T-shirt, smirks as he listens to the judge during sentencing on Tuesday in Chardon, Ohio.

Editor's warning: This story contains graphic content. 

An Ohio judge has sentenced T.J. Lane, the Ohio teen charged with shooting three students to death and wounding three others last February, to life in prison without the possibility of parole. 

Lane showed up to his sentencing wearing a white T-shirt with the word "KILLER" in capital letters scrawled on it -- the same word police say he had emblazoned on his shirt the day of the shootings at Chardon High School.

Lane, 18, pleaded guilty last month to all charges against him in the Feb. 27, 2012, shootings, in which he opened fire on a cafeteria table full of students in the rural community of Chardon.

In a brief statement during his sentencing on Tuesday, Lane flipped his middle finger at people in the courtroom, which included family members of his victims, reported NBC affiliate WKYC.com. He revealed his "KILLER" T-shirt to the court once he was inside, taking off a blue button-down he had worn on the way in, the station reported.

Pool / The News-Herald via AP

T.J. Lane unbuttons his shirt during sentencing Tuesday in Chardon, Ohio.

Three students -- Demetrius Hewlin, 16; Russell King Jr., 17; and Daniel Parmertor, 16 -- were killed last February. Nate Mueller and Joy Rickers were wounded, as was Nick Walczak, who is paralyzed from the waist down, according to Reuters. 

Lane has not given a motive for the shootings, which rocked the tiny town 30 miles outside Cleveland. He gave only a short, defiant statement in the courtroom on Tuesday: "This hand that pulled the trigger that killed your sons now masturbates to the memory. F--- all of you."

Gasps were heard in the courtroom as Lane then proceeded to stick up his middle finger at both his own relatives and those of his victims, The Cleveland Plain Dealer reported. Some people started crying.

Geauga County Judge David Fuhry sentenced Lane to three life sentences without eligibility for parole for three counts of murder, plus 8 years for a fourth count of attempted aggravated murder, 6 years for a fifth count of attempted aggravated murder, and 6 years for a sixth count of felonious assault.

In handing him the sentences, Fuhry said Lane lacked remorse for the killings. Lane was ruled mentally competent enough to stand trial last year despite evidence he suffers from hallucinations and psychosis. Fuhry said Tuesday that court examinations showed Lane faked mental illness and was such a smart student that he was set to graduate from high school early, Reuters reported. 

The families of the boys who died in the shooting have attended every one of Lane’s court hearings, The Plain Dealer said. Other victims' family members also attended Tuesday's sentencing, and read statements to the court ahead of Lane's sentencing.

"Because of you, our quiet little town will never be the same. Why? Why did you do it? Why?" Holly Walczak, mother of paralyzed victim Nick Walczak, said in court on Tuesday. Lane smiled as she read her statement, The Plain Dealer said.

Dina Parmertor, mother of slain victim of Daniel, said, "I want you to be ensured years and years of pain, which in my opinion is not enough. You don’t deserve to take another breath while my 16-year-old son lies in the ground because of your cold, disgusting actions."

"You’re a pathetic excuse for a human being. In fact, you're not even human. You’re a monster," she added, according to The Plain Dealer.

Lane's sister, Sadie, who was in Chardon High School's cafeteria when her brother opened fire, also spoke on Tuesday, talking to reporters outside of the courthouse after the sentencing.

"The brother in the courtroom and that did this is not the brother I knew," she said, offering her condolences to victims' families. 

She described the moment she learned from a police officer who the shooter was last February. 

“Along with other students, I heard the gunshots and screams, ran for my life, ducked under tables, hid in the teachers’ lounge, not knowing who the shooter was,” Sadie Lane said. "When those words hit me, I shook and cried and denied that all this could be true."

She said she hoped for some good to come from the situation. 

"It may be hard for some to understand, but I love my brother, and I hope he can touch other lives in a positive way," she said.

Lane lived with his grandparents and attended an alternative school for students who haven't succeeded in traditional schools. He was waiting for the bus to his school from Chardon High when he began shooting from a .22-caliber semiautomatic Ruger handgun last February, according to police reports. 

He was taken into custody a short distance from where the shootings happened.

Reuters contributed to this report.

This story was originally published on Tue Mar 19, 2013 8:59 AM EDT

WXIA

Scene outside Price Middle School in Atlanta, Ga., after a shooting Thursday.

A 14-year-old boy was shot and a teacher was injured at a middle school in Atlanta on Thursday afternoon but an armed officer was able to disarm the suspect minutes after the incident, officials said.

Police said the shooting took place shortly before 2 p.m. when a student fired several rounds in the courtyard of Price Middle School, a newer school southeast of downtown Atlanta.  

Live video from NBC station WXIA-TV showed police, emergency vehicles and an ambulance swarming the area as crowd of anxious parents flooded toward the school. 

Police said the wounded boy was taken "alert, conscious and breathing" to the hospital.

WXIA, citing school district and fire department officials, reported that he was shot in back of the neck. The wound was not considered life threatening. The teacher suffered cuts and bruises during the panic of the incident, police said.

A student at the school was in custody, police said. Atlanta Police Chief George Turner said a resource officer at the school, an armed off-duty Atlanta officer, was able to disarm the suspect shortly after the shooting.

Walker, who said her daughter is an eighth-grader at the school, told The Associated Press that she received a text from her daughter about the shooting.

"Ma, somebody's shooting and somebody got shot." Walker said. She jumped into her car and was thinking "just hurry up and get there."

The school was placed in lockdown, and all other students were safe, school officials said. Students were kept at the school for hours, but were reunited with their parents by about 5 p.m.

Atlanta Mayor Kasim Reed said in a statement that he is very concerned about the incident and gun violence. 

"Gun violence in and around our schools is simply unconscionable and must end," Reed said. "Too many young people are being harmed and too many families are suffering from unimaginable and unnecessary grief. I pray that the student who was shot today at Price Middle School in southwest Atlanta recovers quickly and can return home to family and friends."

Atlanta Public Schools Superintendent Erroll Davis said the school has metal detectors and officials were still trying to determine how the gun got on campus

The Associated Press contributed to this report.

Joshua Ball/The Ashland Daily Independent via AP

Members of the Perry County Sheriff Office respond to the scene at Hazard Community College, Jan. 15, after a shooting at the school in Hazard, Ky. Authorities say two people were shot and killed and a teen was wounded in the parking lot.

Updated 12:50 a.m. ET: Two people were killed and a teenager was wounded in the parking lot of a Kentucky community college, authorities said.

The shooting took place before 6 p.m. at Hazard Community and Technical College, according to LEX18.com. The teenager was flown to the University of Kentucky hospital, 120 miles away.

Hazard Police Chief Minor Allen said the shooting could be could be related to a domestic situation, the Lexington Herald-Leader reported. The suspect, identified by police as Dalton Stidham, turned himself in to Kentucky State Police, the Herald-Leader reported. Police said Stidham faced two counts of murder and one count of attempted murder, according to WLEX TV.

Police identified the victims as Caitlin Cornett and her uncle, Jackie Cornett. The injured teen is Jackie Cornett's daughter, WLEX reported.

Caitlin Cornett was a student at the college, according to a WLEX reporter. Hazard Assistant Chief Joe Engle told the Herald-Leader that preliminary information indicated that Stidham and Caitlin Cornett had a child in common and were meeting in a parking lot of the school to exchange the child for visitation.

A notice on the school’s website said that an “incident” had occurred on campus, adding, “We ask that you please stay away from campus at this time.” 

The college's academic programs range from associate's degrees in arts and sciences to career-focused training in mining technology and heavy-equipment operation.

--The Associated Press and NBC's Denise Ono contributed reporting.

Baltimore County Police Department / AP

Robert Wayne Gladden, Jr., 15, of Baltimore.

PERRY HALL, Md. - A 15-year-old sophomore at a suburban Baltimore high school who made references to murder-suicide on Facebook has been charged as an adult in the shooting of a classmate on the first day of school, authorities said Tuesday.

Robert Wayne Gladden Jr. was being held without bail on charges of attempted first-degree murder and first-degree assault, Baltimore County police said. A preliminary hearing was scheduled for Sept. 7. The state's attorney's office said it did not know if he had a lawyer.

Gladden's last status update on his Facebook page, posted the morning of the shooting, read: "First day of school, last day of my life. ... f--- the world."

His father told The Associated Press that his son had been bullied. Baltimore County Police Chief James Johnson said at a news conference Tuesday that he was aware of the reported bullying, but he said Gladden has not indicated in conversations with detectives that bullying was a motive for the shooting. His father did not disclose other possible motives.

Gladden continues to cooperate with investigators and was undergoing a mental health evaluation, Johnson said.

Gladden rode to school on the bus Monday morning with a bag containing a disassembled shotgun, 21 rounds of ammunition and a bottle of vodka, Johnson said.

Steve Ruark / AP

A Baltimore County police officer speaks to a parent as students are evacuated from Perry Hall High School after a student was shot and critically wounded on the first day of classes on Monday, Aug. 27.

When he arrived at school, Gladden went to his first two classes, Johnson said. On the way to the cafeteria, he stashed the bag with the shotgun in a restroom, the chief said. A short time later, he returned to the restroom and assembled the gun, which he then hid beneath his clothes, Johnson said.

Previous report: Student shot at Maryland high school on first day of class

Upon entering the cafeteria, he pulled out the gun and fired a shot toward a lunch table, according to charging documents. A 17-year-old classmate, Daniel Borowy, was struck in the back.

Borowy is a special needs student, according to NBC affiliate WBALTV.com. He remained in critical condition Tuesday at Maryland Shock Trauma Center, a hospital spokeswoman said. His family issued a statement asking well-wishers to keep him in their thoughts and prayers and asking for privacy.

Teachers and school staff rushed toward Gladden, and in the ensuing struggle, he fired another shot that hit the ceiling, investigators said in the documents. The staffers were able to get the gun away from him and he was arrested by a school resource officer.

Witnesses credited guidance counselor Jesse Wasmer with getting the gun away from Gladden.

Gladden sipped from the vodka bottle before the shooting but did not drink enough to become intoxicated, Johnson said.

The teen got the shotgun from his father's house, Johnson said. The weapon was manufactured before 1968 and was of legal length, and police were trying to determine whether it was properly registered, he said.

On his Facebook page, Gladden referred to mass murderer Charles Manson and gave himself the nickname "SuicidalSmile." The page, identified by classmates as belonging to the suspected shooter, was just launched in July, and the three photos of Gladden all show his face hidden behind long, dark hair. He describes himself as a "metalhead" and a fan of musicians Marilyn Manson and Slipknot.

The suspect's father, Robert W. Gladden, told the AP Monday evening that his son was the shooter and indicated his son had been bullied. He gave no further details.

A woman who was also at the home in Middle River and said she was related to the elder Gladden gave the following statement on the family's behalf: "We are horrified. We did not see this coming and our thoughts and prayers are with the victim and the victim's family."

Court documents show Gladden's parents divorced in 2010, reported WBALTV.com. The news station went to the house where Gladden lives with his mother on Monday afternoon; a sign on the door read "We don't call 911," and had a picture of a revolver on it, reporters said.  No one in the house would comment on the shooting.

Police also executed a search warrant at the Kingsville home of Gladden's mother and stepfather and arrested the stepfather — Andrew Piper, 43 — on illegal gun and drug possession charges, police said. The charges against Piper had nothing to do with the school shooting, Johnson said, but he noted that Gladden lived part-time at that address.

Classes resumed Tuesday at the school amid a low-key police presence. About 150 students turned out for a prayer vigil organized by local churches on the school grounds. Some students wore T-shirts and bracelets reading "Pray for Daniel" and "Team Wasmer" in reference to the victim and the guidance counselor.

Shane Boyer, 44, who was dropping off his 13-year-old daughter Corinne, said the vigil helped calm students still dealing with the shooting. Boyer said he knew immediately that his daughter was safe after the shooting because he received text messages from her. One read, "Someone just shot a gun in lunch," followed by another that said, "I ran out I am do (sic) scared there's helicopters + cops + we are all outside."

Perry Hall is a middle-class community along the Interstate 95 corridor, northeast of the city of Baltimore. The school is the largest in the county, with 2,200 students.

The Associated Press contributed to this report.

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Aaron Josefczyk / AP

T.J. Lane, 17, appears in juvenile court in Chardon, Ohio, on Thursday.

The 17-year-old charged with fatally shooting three students and injuring two others at a high school in Chardon, Ohio, will be tried as an adult, a judge ruled Thursday.

T.J. Lane has confessed to the massacre, officers said in court Thursday. And he allegedly told police he purposely fired at his victims' heads so "they wouldn't suffer," reported NBC affiliate WKYC.

When Lane was arrested on Feb. 27, the day of the shootings, he was wearing a T-shirt with the word "killer" on it, officers testified, according to WKYC.

Read original story on WKYC.com

The decision to charge Lane as an adult came after a hearing in juvenile court. Judge Timothy Grendell cleared the courtroom briefly Thursday morning to play security camera footage from the shootings for the court. An officer who saw it described it as "horrible and gruesome," according to WKYC.

Lane was declared competent to stand trial in a previous hearing. Being tried as an adult means he could face life in prison, reported WKYC.

He's currently being held without bail in the Portage County juvenile facility, NBC reported. He is scheduled to be transferred to the Geauga County Jail, an adult facility, sometime after June 7, unless his attorneys get a waiver.

The fact that Lane admitted shooting students in the head so they wouldn't suffer shows prior calculation and that Lane was lucid during the massacre, Geauga County Prosecutor David Joyce said, according to The Cleveland Plain Dealer.

Geauga County Deputy Jon Bilicic told the court he found Lane about a mile from the school where the shots had been fired. He was sitting on the side of the road, wet from the waist down, and shivering. A knife was laying next to him in the street. He said Lane told him he had just "killed a bunch of people," reported NBC. Bilicic said he asked Lane why, and he responded, "I don't know." Later in the investigation, Lane added, "I don't really understand myself."

Bilicic pressed Lane about his victims, asking if he had shot female or male students, and how many he had shot. Lane replied, "I have no idea," reported The Plain Dealer.

Students Demitrius Hewlin, Russell King and Daniel Parmertor died from gunshot wounds sustained that day. Students Nick Walczak and Joy Rickers were wounded, but survived.

Bilicic said he then questioned Lane about his motive, asking if he was depressed, suicidal or on drugs. Lane answered "no" to everything, the paper reported. He hadn't been bullied and wasn't upset with anyone at the school.

"I don't get angry. I have no problems with people; they don't even talk to me," Lane allegedly said. He said he got the gun from an uncle's house the day before, and said he had been thinking about the shooting for about a month, according to The Plain Dealer.

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The mother of the third-grade boy who brought a gun to school that went off, injuring a classmate, has been charged, as has her boyfriend, the Kitsap Sun newspaper reported Monday.  

Prosecutors say Jamie Lee Chaffin, 34, and Douglas L. Bauer, 50, of Bremerton, Wash., are responsible for Chaffin's son obtaining the .45-caliber handgun. The boy, 9, had told his friends he planned to run away from his uncle’s house, where he lives, and that he planned to bring a gun with him for protection.

Girl shot: 9-year-old in orange jumpsuit cries in court

Chaffin, a felon who also uses the last name Passmore, was also charged with unlawful possession of a firearm. In 2007, Chaffin was convicted of forgery and delivering marijuana. She does not have custody of her son. Prosecutors say that he only occasionally visited her, the Kitsap Sun reported.

Police believe the boy took the gun from the glove compartment of his mother’s car and then packed it in his backpack on Feb. 22. One minute before the bell rang that day, he dropped the backpack on his desk, and it discharged, shooting 8-year-old Amina Kocer-Bowman, who remains at Harborview Medical Center in Seattle.

The News-Tribune of Tacoma reported that she has undergone at least five surgeries and that the bullet shattered Amina’s elbow and punctured her abdomen, liver, pancreas and intestines. The bullet is lodged in her spine and doctors say it probably cannot be removed.

The boy was charged on three counts. Kitsap County prosecutors said he will likely serve probation.

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