CHICAGO: A Missouri mother foiled her son's plot to kill people at the latest Twilight film when she told police he was off his medication and had bought assault weapons, court documents showed Friday.

Police found Blaec Lammers, 20, at a Sonic fast food restaurant on Thursday after his mother told them she was worried because the guns he'd purchased were similar to those used in the recent massacre at a Colorado screening of Batman.

Lammers went quietly to the police station where he initially told detectives he bought the guns to go hunting, a probable cause statement said.

But he opened up when they began discussing recent shootings and said he “had a lot in common” with the shooters.

“Lammers stated that he was quiet, kind of a loner, had recently purchased firearms... and had homicidal thoughts,” Detective Dustin Ross wrote.

He then admitted that he'd bought the guns “with the intention of shooting up the movie theater” in his hometown of Bolivar, Missouri on Saturday night.

“Blaec Lammers stated that he then got to thinking about it and realized that he might run out of ammunition so he decided he would go and shoot people at Wal-Mart,” Ross said.

He told the officers he planned to “walk into the store and just start shooting people at random.”Lammers told police he had purchased 400 rounds of ammunition and decided that if he ran out “he would just break the glass where the ammunition is being stored and get some more and keep on shooting until the police arrived.”Lammers, who said he'd never fired a gun before he practiced on Tuesday, told police he planned to give himself up once they arrived.

He was charged Friday with one count of making a terrorist threat, one count of assault and one count of armed criminal action.

He was previously arrested in 2009 after stating that he wanted to stab a Wal-Mart employee to death and following an employee around the store until police arrived, the charging papers said.