5 Disturbing Things We Learned Today About Sandy Hook Shooter Adam Lanza

— -- intro: Two years after the Sandy Hook Elementary School massacre, Connecticut's Office of the Child Advocate released a report today detailing the mental health profile of gunman Adam Lanza, noting potential missed opportunities.

The Office of the Child Advocate, which investigates all child deaths in Connecticut for prevention lessons, released a 114-page report today.

Lanza was 20 on Dec. 14, 2012 when he shot his mother, Nancy Lanza and then went to the Sandy Hook Elementary School where he massacred 20 first-graders and six educators before taking his own life.

Inside Adam Lanza's Bedroom

Sandy Hook Gunman's Father Wishes Son Was Never Born

The report's authors say they "looked for any warning signs, red flags, or other lessons that could be learned from a review of AL's life," referring to Lanza. "This report cannot and does not answer the question of 'why' AL committed murder," the authors wrote.

Here are some of the disturbing things we learned about Lanza.

quicklist:title: Lanza had a falling out with his "one and only friend" months before.

text: Among the factors that may have caused Lanza "anxiety" before the shooting were the possibility of moving with his mother and a "falling out" with an unnamed friend.

"AL was acquainted with another adolescent that he played [video game Dance Dance Revolution] with on a regular basis," the report said. "They would meet a few times per month to either play the video game or go to the movies. AL and his friend talked about multiple topics, including computers, chimp society, human nature, morality, prejudice, and sometimes about his family. AL told his friend that he had a strained relationship with his mother."

Timeline of Sandy Hook Elementary Shooting

"AL would sometimes talk with this friend about the topic of mental health or depression, though he never indicated that he was diagnosed with anything. He did tell his friend that mental health issues were not a reflection of the character of a person, but were symptoms of something else going on inside a person," the report said.

"AL and the friend also talked about their interest in mass murderers or serial killers, but this was just considered to be a mutual morbid interest," the report said. "Both he and his acquaintance liked horror movies."

But in June 2012, Lanza "and his primary acquaintance had a falling out and stopped spending time together," the report said, "after a dispute over a movie."

quicklist:title: His "social-emotional" challenges increased after fourth grade.media: 27090853text:

Lanza was referred for special education preschool services at age 2.

"[Lanza] was presented with significant developmental challenges from earliest childhood, including communication and sensory difficulties, socialization delays, and repetitive behaviors," the report states. "He was seen by the New Hampshire 'Birth to Three' intervention program when he was almost three years old and referred for special education preschool services."

Watch: Sandy Hook Shooter's Father Describes How Adam Lanza Changed

Early in the fourth grade, Lanza left the special education program because he had "met all speech goals," the report states.

During Lanza's early elementary school years, his parents still lived together in the family home in Sandy Hook, but they separated in 2002 when Lanza was in the fifth grade.

"[Lanza] was described by some as seeming happy, smiling, and participating in community and school activities," the report states. "At the same time, however, more red flags for developmental and mental health concerns remained or emerged. AL began perseverative hand washing, avoiding contact with other people, and becoming increasingly fearful. By fifth grade, AL had written and submitted 'The Big Book of Granny' — a significant and violent text — and following that school year, his struggles began to escalate."

quicklist:title: His preoccupation with violence may have been "largely unaddressed."media: 27090969text: The report raises questions about how there may have been missed opportunities with Lanza, including whether his family's wealth and race were factors.

"Would [Lanza's] caregivers’ reluctance to maintain him in school or a treatment program have gone under the radar if he were a child of color?" the report asks.

Lanza's mother transferred him to a Catholic school for the fourth quarter of seventh grade.

"A teacher at the school later reported that he presented very differently from the other children," the report states.

Schools Helped Newton Shooter's Mom 'Appease' Him

Newtown Shooter Lanza Had Sensory Processing Disorder

According to the teacher's account in the report, he had "very distinct anti-social issues."

"AL would write ten pages obsessing about battles, destruction and war. I have known 7th grade boys to talk about things like this, but AL’s level of violence was disturbing. I remember showing the writings to the principal at the time, AL’s creative writing was so graphic that it could not be shared," the teacher's account in the report states.

"It was not the primary purpose of this investigation to explicitly examine the role of guns in the Sandy Hook shootings," the report said. "However, the conclusion cannot be avoided that access to guns is relevant to an examination of ways to improve the public health. Access to assault weapons with high capacity magazines did play a major role in this and other mass shootings in recent history."

The report states, "[Lanza] and his parents did not appear to seek or participate in any mental health treatment after 2008."

quicklist:title: While he may have been described as "gifted," his cognitive abilities may have been just "average."media: 27088216text:

On Oct. 24, 2006, almost a year after a community psychiatrist first evaluated Lanza, he was seen at the Yale Child Study Center by a clinical psychiatrist, the report states. "The evaluation was purportedly to determine if AL had Obsessive Compulsive Disorder in the context of a putative diagnosis of Asperger Syndrome."

The report details how his parents said that their son was "angry" about having to go to Yale and he refused treatment.

"The Yale APRN [Advanced Practice Registered Nurse], in a present day interview, offered her view that AL may not, in fact, have had an Autism Spectrum Disorder, but rather that he suffered from disabling anxiety and Obsessive Compulsive Disorder," the report states.

More Highlights From Report on Sandy Hook Shooter

Meanwhile, the report indicates his parents may have had difficulty accepting his disabilities.

"While it is not uncommon for parents to struggle to identify and accept their child as suffering a disabling impairment, the Yale Child Study Center clinicians who evaluated and treated AL felt that his parents, and certainly his mother, may have had greater than average difficulty with accepting the extent of AL’s disabilities," the report states. "Yale did not think that AL was gifted and unique, pointing to the average cognitive abilities captured by the school’s psychological testing."

"Adam Lanza's parents (and the school) appeared to conceptualize him as intellectually gifted, and much of [his] high school experience catered to his curricular needs," the report said. "In actuality, psychological testing performed by the school district in high school indicated AL’s cognitive abilities were average."

quicklist:title: Why Lanza and his father had a "falling out." media: 27087784text: Lanza stopped responding to his father's emails around 2010, the report states.

"After AL began declining to spend time with Mr. Lanza, Mr. Lanza would regularly send emails to him asking him how he was doing," the report states. "He asked AL to join him at events or other activities they had previously enjoyed, including arcades, shooting ranges, or coin shows."

Sandy Hook Gunman's Father Wishes Son Was Never Born

The "falling out" may have had to do with Lanza's desire to take college courses at Norwalk Community College, the report states.

"AL wanted to carry a full course load but Mr. Lanza said he couldn’t handle that and wasn’t being realistic," the report states. "This may have been the last time that AL and Mr. Lanza actually spoke or emailed reciprocally. Mr. Lanza continued to let AL know that he wanted to see him."