Former NFL running back Joe McKnight was shot dead in an apparent road rage incident in Louisiana.

A witness at the scene told the Times-Picayune that she saw two men arguing at an Terrytown intersection Thursday afternoon shortly before 3 pm. One man was yelling, while the other – later identified as 28-year-old McKnight – appeared to be apologising.

The alleged shooter, she said, shot McKnight before telling him, “I told you don’t f**k with me.” He fired another shot after making the statement, she said.

McKnight attended John Christian Curtis School in River Ridge – just southeast of Baton Rouge. He went on to become a star player with USC. In 2010, McKnight was picked in the fourth round of the NFL draft and played for the New York Jets and Kansas City Chiefs until 2014.

Jefferson Parish Sheriff Newell Normand identified the suspected shooter as Ronald Gasser, 54. Gasser stayed on the scene and turned his gun over to authorities upon their arrival. He remains in custody and is being questioned, Mr Normand told reporters.

First responders performed CPR on McKnight at the scene, but were unable to revive him.

His cousin Roxanne Lundy was at the scene after a relative told her what happened.