Ronald Gasser had appealed his manslaughter conviction, citing Louisiana's Stand Your Ground law and his 10-2 jury conviction.

JEFFERSON PARISH, La. — The man who shot and killed former NFL running back Joe McKnight in a 2016 road rage incident will remain in prison, after a court denied an appeal of his conviction Wednesday.

Ronald Gasser, 57, of Gretna, was found guilty of manslaughter in January 2018 after he killed 28-year-old McKnight in Terrytown during a road-rage incident that started on the Crescent City Connection.

McKnight, born in Kenner, was a John Curtis High School football standout who excelled at running back for the University of Southern California and was drafted into the NFL in 2010. He was under contract for a Canadian Football League team at the time of his death.

Gasser was sentenced to 30 years in prison after being convicted 10-2 by a non-unanimous jury, despite the defense's argument that the killing was justified under Louisiana's "Shoot the Intruder" law.

Last month, however, Dane Ciolino with the Loyola University Law School went to the Louisiana Fifth Circuit Court of Appeal in Jefferson Parish to appeal on behalf of the Gretna man.

According to Ciolino, the evidence used in the original trial stood out to him so much that he and his students took on Gasser's chase free of charge.

"Because the character evidence, and I teach evidence, was so egregious, was so prejudicial, that it never should have been a part of this trial," Ciolino said.

Ciolino's appeal consisted of five potential errors he found in the trial that would warrant a reversal of the conviction. Four of those errors dealt with the use and application of evidence against Gasser's self-defense claim.

Specifically, Ciolino called trial testimony about Gasser's arrest for an similar apparent road-rage incident a decade earlier a "sneaky pile of prejudicial evidence."

After reviewing those arguments, a panel of three appellant judges upheld Gasser's conviction, maintaining his shooting of McKnight on Behrman Highway and Holmes Boulevard in Terrytown did not meet the standard of the state's Stand Your Ground law.

"There is nothing in the record to suggest a forcible entry as Mr. McKnight placed his hands on the open passenger-side window of defendant’s vehicle. In our opinion, even Mr. McKnight’s alleged lunging into the car, as per defendant’s statement, does not constitute a forcible entry," the affirmation reads.

The fifth error in the appeal dealt with Gasser's conviction by a non-unanimous jury, a Jim Crowe era practice that was voted out in the state this year.