CHICAGO (CBS)–Cook County Sheriff’s Police hope the public can help answer questions about the shooting death of a security guard at a south suburban bar.

Investigators on Tuesday released surveillance photos of three men who were at the scene of the shooting of Jemel Roberson, who was working security at Manny’s Blue Room Lounge Nov. 11 when he was fatally shot by a still-unnamed Midlothian police officer.

The police officer who shot Roberson was there responding to a call of a shooting at the bar earlier that night.

Witnesses claim they informed officers as they arrived that Roberson was a security guard.

The officer involved is on paid leave during the investigation.