Last Updated 11:12 a.m.
NEWTOWN, Conn. When the parents of Connecticut school shooter Adam Lanza divorced in 2009, their legal documents offer no hints of an acrimonious split and make no mention of any lingering mental health or medical issues for the then-teenage boy.
Newly-public divorce paperwork shows that Nancy Lanza had the authority to make all decisions regarding her son's upbringing.
The court papers were made public Monday.
The divorce was finalized in September 2009, when Adam Lanza was 17.
There is no evidence of bitterness in the court file, no exchange of accusations or drawn out custody disputes.
Nancy and Peter Lanza had joint legal custody of Adam but he lived with his mother. The parents agreed to consult and discuss major decisions affecting Adam's best interests. In instances where the parents couldn't agree, Nancy Lanza "shall make the final decision," Judge Stanley Novak wrote on Sept. 24, 2009.
Nancy Lanza, who was once a stockbroker for John Hancock in Boston, married Peter Lanza in Kingston, N.H., in June 1981. The divorce file said the marriage "has broken down irretrievably and there is no possibility of getting back together."
The divorce agreement gave Nancy Lanza $265,000 in alimony last year.
It makes no mention of any mental health issues regarding her son.
As part of the divorce, Nancy Lanza was ordered to attend a parenting education program. The provider, Family Centers Inc., certified that she completed the program on June 3 and June 10, 2009. The document says only that Lanza "satisfactorily completed the program."
The documents also say Adam Lanza has lived his entire life at the Newtown home where he shot his mother to death, before going to Sandy Hook Elementary School in Newtown, Conn., on Friday morning and killing 20 children and six adults before taking his own life.
A Connecticut officials said Nancy Lanza was found in bed, in her pajamas, shot four times in the head with a .22-caliber rifle.
Adam Lanza is believed to have used a Bushmaster AR-15 rifle in the school attack, a civilian version of the military's M-16 and a model commonly seen at marksmanship competitions. Versions of the AR-15 were outlawed in the United States under the 1994 assault weapons ban; that law expired in 2004, and Congress, in a nod to the political power of the gun-rights lobby, did not renew it.
Neighbors told CBS News that Nancy Lanza was a gun enthusiast and often took Adam Lanza target shooting with her; it was her guns Adam used against her and the women and children at Sandy Hook.
CBS News' Pat Milton reports a source briefed on the investigation said that Nancy Lanza was demanding of her children. Even though Adam was highly intelligent, she pressed him to high standards and even pressed her sons to measure up at the shooting range where she taught them to shoot, the source said.
Federal agents have concluded that Adam Lanza had visited an area shooting range, but they do not know whether he practiced shooting there. Agents determined Lanza's mother visited shooting ranges several times, but it's not clear whether she took her son or whether he fired a weapon there, said Ginger Colbrun, a spokeswoman for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.
Adam's aunt, Marsha Lanza of Crystal Lake, Ill., said that Nancy Lanza kept guns for own safety, and had something of a survivalist mentality; she was worried about protecting her home if the economy went south.
Money was not an issue for the family. Marsha said her ex-husband left Nancy "well-off . . . She didn't have to work."
However, a friend of Nancy Lanza, local landscaper Dan Holmes, said she evidently still suffered from a bad divorce and could be pretty vocal about her ex-husband ... years afterwards."
Peter Lanza, a tax director who lives in Stamford, Conn., issued a statement relating his own family's anguish in the aftermath.
"Our family is grieving along with all those who have been affected by this enormous tragedy. No words can truly express how heartbroken we are," he said. "We are in a state of disbelief and trying to find whatever answers we can. We too are asking why. ... Like so many of you, we are saddened, but struggling to make sense of what has transpired."