The shooting happened in April 2023 in the parking lot of Miraj at 8801 Milwaukee Ave. in Niles.
Neary three years after the deadly shooting, Alan Kettina of Northbrook was found guilty on six charges related to murder.
On Wednesday, he was sentenced to 60 years in prison.
Kettina was employed with the Cook County Department of Corrections at the time of the shooting, police said.
RELATED | Niles shooting: Cook County Corrections officer charged in fatal shooting outside Miraj restaurant
Mark Asber, 22 of Niles, was shot outside the nightclub. He died at a local hospital, according to the Cook County Medical Examiner's Office.
Investigators said the victim and suspect knew each other prior to the shooting.
Prosecutors said Kettina shot Asber in the back as he was walking away.
Kettina's attorneys claimed the victim intimidated and threatened to harm him and his family if he did not smuggle contraband into the Cook County Jail.
The video in the player above is from an earlier report.