AUSTIN -- A trial is set for Monday in Travis County against a man accused of punching an Austin architect to death.
Preston Sharpnack is charged with manslaughter and aggravated assault after police say he punched Matt Casey during Labor Day Weekend in 2012.
Sharpnack's mother says her son was defending himself and a friend but never meant to kill Casey.
"I don't think Preston meant to knock the man down and kill him. I think he meant to get him to understand what he was doing, was continuing on something that needed to be stopped," said Bettie Sharpnack, Preston's mother.
The video shows Sharpnack and his female friend Renee Jones panhandling near 6th and Neches. Sharpnack says Casey began screaming at the couple. Jones walks toward Casey and pushes him. The two begin pushing and shoving each other. Sharpnack is seen in the background, diffusing the situation.
Sharpnack and Jones walk away in the video. Off camera, Sharpnack says Casey followed her son, and he punched Casey.
Doctors say Casey didn't die from the punch but rather from the strike of his head against the ground.
Sharpnack was offered a plea agreement of eight years, but lawyers say he should elect to have a jury trial.
"My hope for Monday is the jury as well as everyone else will have an open mind, listen to the evidence and affirm the right of someone to defend themselves from a senseless attack by a drunk man on 6th Street," said Malcolm Nettles, Sharpnack's lawyer.
The trial will being Monday at 9 a.m. in Judge Karen Sage's courtroom.