Former USC star running back Joe McKnight was murdered in Terrytown, Louisiana on Thursday afternoon.
Family members identified McKnight's body at the crime scene.
A witness, who declined to give her name, said she was leaving a store in the area when she saw a man at the intersection yelling at another man, who was trying to apologize. The man who was yelling shot the other man more than once, she said.
She said the shooter shot the man, stood over him and said 'I told you don't you f--- with me.' Then he fired again, she said.
McKnight was selected in the fourth round of the 2010 NFL Draft by the Jets.
He last played in the NFL in 2014 for the Chiefs, where he caught six passes for 64 yards and two touchdowns over two games.
His season came to an end when he suffered a torn Achilles' tendon in September 2014.
The 28-year old played in the CFL this year.