Xavier Jerrod Cerf was fatally stabbed Monday when, according to investigators, several students tried to stop him from stealing a car behind a fraternity house.
Investigators say Cerf told the man confronting him that he had a gun and reached for his waistband. That's when USC student Ivan Gallegos grabbed his hand and stabbed him in the chest.
DA George Gascón says investigators determined Gallegos was in genuine fear for his life and was acting to protect himself and others.
Detectives later determined Cerf did not have a gun.
Cerf's mother, Yema Jones, is in Houston, some 1,500 miles from where the incident unfolded.
She said she is focused on trying to bring her son's body back to Texas where he was raised.
"I haven't had time to grieve because my mind is going on what I need to do to get my son here," Jones said. "Away from the people who hurt him."
Jones says her son is the father of a three-year-old boy.
The family now wears purple bracelets with the letters LLX for long live Xavier.
Police described Cerf as homeless, but his mother says that was not true.
"I want them to say his name. His name is Xavier Jerrod Cerf. He wasn't a homeless man. He had a home."
Jones is calling for the case to be reopened. She questions the finding of self-defense, noting it was the students who first approached Cerf.
"What were you defending? .... If somebody is coming after you, then you defend yourself from that person harming you. Not you coming to that person and harming them."
Jones says her 27-year-old son had recently been released from receiving mental health treatment.
"I'm going to fight for justice for what's mine," she said. "So he can properly rest. Because he didn't deserve that."