Federal agents said Adam Lanza had fired guns at shooting ranges over the past few years but there was no evidence he did so recently in preparation for the massacre, the Associated Press reports.
A spokeswoman for the Bureau of Alcohol, Tobacco, Firearms and Explosives said the gunman and his mother both fired at shooting ranges and had visited ranges together.
Debora Seifert told AP there was no indication "that the shooter engaged in shooting activities in the past six months."
A list of the victims from the US school shooting has been published. Twenty students and six teachers were killed in the massacre.
The most disturbing feature of the rampage is what we do not know. We still have no idea why Adam Lanza acted with this cowardly savagery.
There are reports claiming that Adam Lanza went to the school a day before the massacre. They say he had a major confrontation with staff.