He also wouldn't touch doorknobs, his food had to be arranged on the plate in a certain way, and he changed clothes and washed his hands often during the day. He was a loner at school and was repelled by crowds and loud noises. His mother got rid of a cat because her son didn't want it in the house.
Weeks before the Newtown shooting, Nancy Lanza was concerned about her son and said that he hadn't gone anywhere in three months and would communicate with her by email only, even though they lived in the same house, according to the report.
However, she never expressed fear that she or anyone else was in danger from Adam, the report said. She was in New Hampshire the week before the shooting, arriving home the evening of Dec. 13.
Lanza "was undoubtedly afflicted with mental health problems; yet despite a fascination with mass shootings and firearms, he displayed no aggressive or threatening tendencies," Sedensky wrote.
"Some recalled that the shooter had been bullied; but others — including many teachers — saw nothing of the sort."
Sedensky said the hard drive taken from Lanza's bedroom might hold clues but was so damaged that data will probably never be extracted from it.
A timeline released with the report indicates that nearly six minutes passed between the arrival of the first Newtown police office and the time officers entered the school. The report said officers were operating under the belief there may have been more than one shooter.
Whether the delay made any difference was unclear. The report said Lanza killed himself about a minute after the first officer arrived.
Donna Soto, the mother of slain teacher Victoria Soto, said in a statement that nothing could make sense of the shooting.
"Yes, we have read the report, no, we cannot make sense of why it happened. We don't know if anyone ever will," Soto wrote. "We don't know if we will ever be whole again, we don't know if we will go a day without pain, we don't know if anything will ever make sense again."
Teresa Rousseau, whose daughter Lauren was among the six educators killed at Sandy Hook, said she hasn't read the report.
"It's just too painful to go there," Rousseau said.
Sedensky's report is a summary of a much larger state police evidence file that is expected to be released at a later date.
Sedensky has gone to court to fight release of the 911 tapes from the school to spare the victims' families the anguish. A judge said Monday he will listen to the recordings before deciding whether they can be made public.
The report said the first officer arrived behind the school at 9:39 a.m. Two other Newtown officers then arrived within seconds, and gunshots were heard in the background.
The last gunshot officers heard, which is believed to be the suicide shot by Lanza, was heard at three seconds past 9:40. Newtown officers entered the school at 47 seconds past 9:44, according to the report.
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