Story by the Associated Press; curated by Jason Howerton

NEW HAVEN, Conn. (AP) — Connecticut police released thousands of pages Friday from their investigation into the Newtown massacre, providing the most detailed and disturbing picture yet of the rampage and Adam Lanza’s fascination with murder, while also depicting school employees’ brave and clear-headed attempts to protect the children.

Included in the file were photographs of the home the 20-year-old Lanza shared with his mother. They show numerous rounds of ammunition, gun magazines, shot-up paper targets, gun cases, shooting earplugs and a gun safe with a rifle in it.

Police File on Newtown Yields Chilling Portrait

FILE – This undated identification file photo released Wednesday, April 3, 2013 by Western Connecticut State University in Danbury, Conn., shows former student Adam Lanza, who opened fire inside the Sandy Hook Elementary School in Newtown, Conn., on Friday, Dec. 14, 2012, killing 26 students and educators. (AP Photo/Western Connecticut State University, File)

A former teacher of Lanza’s was quoted as telling investigators that Lanza exhibited anti-social behavior, rarely interacted with other students and obsessed in writings “about battles, destruction and war.”

“In all my years of experience, I have known (redacted) grade boys to talk about things like this, but Adam’s level of violence was disturbing,” the teacher told investigators. The teacher added: “Adam’s creative writing was so graphic that it could not be shared.”

The documents’ release marks the end of the investigation into the Dec. 14, 2012, shooting at Sandy Hook Elementary School that left 20 first-graders and six educators dead.

Lanza went to the school after killing his mother, Nancy, inside their home. He committed suicide with a handgun as police arrived at the school.

The documents also fill in more details about how the shooting unfolded and how staff members looked out for the youngsters.

Teachers heard janitor Rick Thorne try to get Lanza to leave the school. One teacher, who was hiding in a closet in the math lab, heard Thorne yell, “Put the gun down!” An aide said she heard gunfire and Thorne told her to close her door. Thorne survived.

Teacher Kaitlin Roig told police she heard “rapid-fire shooting” outside of the school, near her classroom. She rushed her students into the classroom’s bathroom, pulled a rolling storage unit in front of the bathroom door as a barricade and then closed and locked the door.

She heard a voice say, “Oh, please, no. Please, no.” Eventually, police officers slid their badges under the bathroom door. Roig refused to come out and told them that if they were truly police, they should be able to get the key to the door – which they did.

Others weren’t so lucky.

Police Lt. Christopher Vanghele said he and another officer found what appeared to be about 15 bodies, mostly children, packed in another bathroom “like sardines.” So many people had tried to cram inside the bathroom that the door couldn’t be closed, and the shooter gunned them all down, Vanghele surmised.

The paperwork, photos and videos were heavily blacked out to protect the names of children and to withhold some of the more grisly details of the crime.

In a letter accompanying the files, Reuben F. Bradford, commissioner of the state Department of Emergency Services and Public Protection, wrote that much of the report was disturbing but that it also showed teachers trying to protect their children, law enforcement officials putting themselves in harm’s way, and dispatchers working calmly and efficiently.

“In the midst of the darkness of that day, we also saw remarkable heroism and glimpses of grace,” he wrote.

In the documents, a friend told police that Nancy Lanza reported that her son had hit his head several days before the shootings. And an ex-boyfriend told police that she canceled a trip to London on the week of the shooting because of “a couple last-minute problems on the home front.”

Peter Lanza, who was estranged from his son, told police that Adam had Asperger’s syndrome – a type of autism that is not associated with violence – and exhibited symptoms of being “slightly OCD,” meaning obsessive compulsive disorder.

A former Newtown High student who was in Tech Club with Adam Lanza recalled him pulling his sleeves over his hands any time he was handed an object from someone.

A nurse told police that Lanza’s mother had to do three loads of laundry each day because her son obsessively changed clothes – sometimes changing his socks 20 times daily.

Prosecutors previously issued a summary of the investigation last month that portrayed Lanza as obsessed with mass murders, but the report concluded that Lanza’s motives for the massacre might never be known.

Lanza “was undoubtedly afflicted with mental health problems; yet despite a fascination with mass shootings and firearms, he displayed no aggressive or threatening tendencies,” it said.

Police File on Newtown Yields Chilling Portrait

FILE – In this Dec. 18, 2012 file photo, a police cruiser sits in the driveway as crime scene tape surrounds the home of Nancy Lanza in Newtown, Conn. Nancy Lanza was killed there by her son Adam Lanza, before he forced his way into Sandy Hook Elementary School Dec. 14, 2012 in Newtown, where he killed 26 children and adults. (AP Photo/Jason DeCrow, File)

Police File on Newtown Yields Chilling Portrait

This Dec. 14, 2012 photo released by the Connecticut State Police shows what the evidence report describes as a hard cover copy of “Amish Grace” found in the house where Adam Lanza lived with his mother in Newtown, Conn. The photo was released as part of the evidence gathered by police during their investigation after Adam Lanza gunned down 20 first-graders and six educators with a semi-automatic rifle at Sandy Hook Elementary School on Dec. 14, 2012, in Newtown. (AP Photo/Connecticut State Police)

Police File on Newtown Yields Chilling Portrait

This Dec. 16, 2012 photo released by the Connecticut State Police shows what the evidence report describes as a “Volunteer Thank You Card” for Mrs. Lanza with a pamphlet for a 5th grade “Stepping Up Ceremony” dated June 10, 1999 at Sandy Hook Elementary School, found in the house where Adam Lanza lived with his mother in Newtown, Conn. The photo was released as part of the evidence gathered by police during their investigation after Adam Lanza gunned down 20 first-graders and six educators with a semi-automatic rifle at Sandy Hook Elementary School on Dec. 14, 2012, in Newtown. (AP Photo/Connecticut State Police)

Police File on Newtown Yields Chilling Portrait

This evidence photo contained in a document titled “Sec 15 – Firearm Survey – Savage,” in a report of an investigation released by the Connecticut State Police, Friday, Dec. 27, 2013, shows a weapon. Adam Lanza gunned down 20 first-graders and six educators with a semi-automatic rifle at Sandy Hook Elementary School on Dec. 14, 2012, in Newtown, after killing his mother inside their home. Lanza committed suicide with a handgun as police arrived at the school. (AP Photo/Connecticut State Police)

Police File on Newtown Yields Chilling Portrait

NEWTOWN, CT – UNSPECIFED DATE: In this handout crime scene evidence photo provided by the Connecticut State Police, shows damage done to the front entrance at Sandy Hook Elementary School following the December 14, 2012 shooting rampage, taken on an unspecified date in Newtown, Connecticut. A second report was released December 27, 2013 by Connecticut State Attorney Stephen Sedensky III gave more details of the the Newtown school shooting by Adam Lanza that left 20 children and six women educators dead inside Sandy Hook Elementary School after killing his mother at their home. Handout/Getty Images

Police File on Newtown Yields Chilling Portrait

This photo released by the Connecticut State Police on Friday, Dec. 27, 2013, from a document titled “Sec 8 – Autopsy,” shows evidence pertaining to the Dec. 14, 2012 shooting at Sandy Hook Elementary School in Newtown, Conn. Adam Lanza gunned down 20 first-graders and six educators with a semi-automatic rifle at the school after killing his mother inside their home. Lanza committed suicide with a handgun as police arrived at the school. (AP Photo/Connecticut State Police)

Police File on Newtown Yields Chilling Portrait

NEWTOWN, CT – UNSPECIFED DATE: In this handout crime scene evidence photo provided by the Connecticut State Police, shows a damaged door of the Sandy Hook Elementary School following the December 14, 2012 shooting rampage, taken on an unspecified date in Newtown, Connecticut. A second report was released December 27, 2013 by Connecticut State Attorney Stephen Sedensky III gave more details of the the Newtown school shooting by Adam Lanza that left 20 children and six women educators dead inside Sandy Hook Elementary School after killing his mother at their home. Handout/Getty Images

Police File on Newtown Yields Chilling Portrait

NEWTOWN, CT – UNSPECIFED DATE: In this handout crime scene evidence photo provided by the Connecticut State Police, shows an interior at the Sandy Hook Elementary School following the December 14, 2012 shooting rampage, taken on an unspecified date in Newtown, Connecticut. A second report was released December 27, 2013 by Connecticut State Attorney Stephen Sedensky III gave more details of the the Newtown school shooting that left 20 children and six women educators dead inside Sandy Hook Elementary School. Handout/Getty Images

Police File on Newtown Yields Chilling Portrait

NEWTOWN, CT – UNSPECIFED DATE: In this handout crime scene evidence photo provided by the Connecticut State Police, shows the exterior of the Sandy Hook Elementary School following the December 14, 2012 shooting rampage, taken on an unspecified date in Newtown, Connecticut. A second report was released December 27, 2013 by Connecticut State Attorney Stephen Sedensky III gave more details of the the Newtown school shooting by Adam Lanza that left 20 children and six women educators dead inside Sandy Hook Elementary School after killing his mother at their home. Handout/Getty Images

The new files revealed chaos during the rampage.

Lanza remained silent as he aimed and fired in Room 10, according to an officer who interviewed the mother of one of the surviving students. The woman said her son, who ran from the classroom, recalled the shooter kicking in the door and then firing.

The documents indicate investigators were gentle in their questioning of children, interviewing youngsters only if they or their parents requested it. Some of the parents thought talking openly about the shooting and getting accurate information out would help their children heal.

After the interviews, the children were given a copy of Margaret Holmes’ book “A Terrible Thing Happened” to help them deal with that they witnessed.