New court documents show the pupil confessed to the attack and outline how he took his mother's gun.
The six-year-old student who shot his teacher in the US earlier this year, boasted about the incident saying "I shot [her] dead", unsealed court documents show.
While being restrained after the shooting at a Virginia school, the boy is said to have admitted "I did it", adding "I got my mom's gun last night".
His teacher, Abigail "Abby" Zwerner - who survived - filed a $40m (£31.4m) lawsuit earlier this year.
The boy has not been charged.
The boy's mother, however, Deja Taylor, has been charged with felony child neglect and misdemeanour recklessly leaving a loaded firearm as to endanger a child.
In Ms Zwerner's lawsuit, filed in April, she accuses school officials of gross negligence for ignoring warning signs and argues the defendants knew the child "had a history of random violence
The documents also mention another incident with the same student while he was in kindergarten. A retired teacher told police he started "choking her to the point she could not breathe".
It's probably a case of her thinking she can not defend herself out of fear of backlash. Teachers have been charged with assault when defending themselves from students.
Yeah I don't get this she couldn't do anything because she would get sued is such a reddit argument its a small child you don't have to punch the kid just push them away and hold your arms out don't sit there like a dumb ass and let a 4 year old strangle you to death
She's alive, so she didn't let him strangle her to death. But you bet your ass, any teachers who want to stay in the profession are waiting until there's no other choice before putting their hands on a kid, even if it's just to push them away. And she was like a year away from retirement? Definitely not doing anything to mess that up; many teachers still get pensions if they retire.