Police say the relationship between Adam Lanza and his mother could be key to discovering his motive.

STAMFORD, Conn. – When the parents of Adam Lanza divorced, the settlement left Nancy Lanza with $24,150 a month in alimony payments and able to live a comfortable life to care for her son.

Nancy Lanza, 52, was her son’s first victim on Friday, shot to death in the spacious home they shared, authorities said. Adam then took his mother’s car and some of her guns, went to the Sandy Hook Elementary School, where he forcefully entered the building and opened fire, killing 20 children and six adults before turning a gun on himself.

Funeral services for the children, whose murders wrenched the nation’s heart, began on Monday.

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Friends said the child had Asperger's syndrome, and family and school staffers struggled with it.

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Richard Novia, who formerly advised the Newtown High School tech club that was one of Lanza's few social outlets, said Lanza had been placed in a special program for students who were considered at risk of being bullied--though he had no recollection of Lanza ever being harassed.

In an interview with the Los Angeles Times, Novia said he was told that Lanza had a medical condition that hindered his ability to feel pain, so that if he cut himself or stubbed his toe, he might not even know he was hurt, and could continue to cause harm to himself.

Novia described a nurturing environment at the high school where teachers and students were encouraged to be on the lookout for signs of abuse or emotional trauma, particularly in kids like Lanza.

“We had programs in place to identify the students who would be likely to have been bullied,” Novia said in a phone interview. “I don’t know that he was [bullied] but I do know that when he came to middle school and the high school level, he would have been the type to be a target.”

Even during her son's elementary school years, Nancy Lanza fretted about his schooling.

"She was concerned mainly that Adam wasn't fitting in well in his classroom," said Wendy Wipprecht, whose son had also been diagnosed with a form of autism. She said Lanza was exploring moving her son to a private Catholic school, or home schooling him, but did not attend sessions of any of the local autism parents' support groups in which Wipprecht was involved.

"She may have decided that there wasn't a support group that would fit," Wipprecht said. "Who knows. She may have been overwhelmed."

There is no mention of Adam Lanza’s emotional troubles or any domestic strife in his parents' divorce papers. Last week, Ryan Lanza told investigators that the divorce could have had an impact on his younger brother.

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Peter and Nancy Lanza married in 1981 in New Hampshire. She sued her husband for divorce in 2008, citing irreconcilable differences.

In their 2009 settlement, Nancy and Peter Lanza agreed to joint custody of Adam, then 17, who would live with his mother but have regular visits from his father. It’s not clear how often Peter Lanza visited Adam but he left his ex-wife with sizable alimony payments and agreed to cover their children's medical insurance.

Court records that were available on Monday show that Nancy Lanza was due to receive $289,800 in alimony in 2012, or $24,150 each month. Peter Lanza, an executive at General Electric who was earning an annual salary of about $445,000 in 2009, also agreed to pay for both their sons’ college and graduate school educations and to buy a car for Adam.

They agreed to divide their assets evenly, including sharing their Boston Red Sox tickets. Peter Lanza left the large house on Yogananda Street in Newtown, Conn., to his ex-wife and moved into an apartment in Stamford.

Each separately completed six hours of parenting education, which is required under Connecticut state law in divorce cases for parents of children younger than 18. The classes are designed to train parents to help children cope with divorce.

 “We too are asking why,” Peter Lanza said in a statement released over the weekend. “We have cooperated fully with law enforcement and will continue to do so. Like so many of you, we are saddened, but struggling to make sense of what has transpired.”

Authorities on Monday continued to pore over damaged electronic equipment including a computer looking for clues to any possible motive for the deadly rampage.