Pennsauken Police Chief John Coffey offered a $500 reward Tuesday that he hopes will help him figure out what happened on the night two off-duty officers were injured in a fight at a bar and bowling alley.

The officers suffered facial injuries May 7 at Pinsetter Bar & Bowl on Maple Avenue before police responded to a call close to 11 p.m. about a fight.

At least one other person was injured, Coffey said.

One officer submitted a written report. Two others, on advice of counsel, have declined to do so.

Coffey hopes the reward will lead to an arrest and an assault conviction.

"I don't know the truth," he said. "That is the reason why I felt it was important to post a reward."

Coffey said he is putting up his own money for the reward. He said that getting to the bottom of the issue is "important for the reputation of this department."

Responding officers reported that tables were overturned and there was broken glass on the floor, Coffey said. Authorities are trying to pinpoint what sparked the fight and have interviewed about a dozen people.

Pete Dickinson, a general manager at Pinsetter, said there was a fight inside the bar sometime after a spring celebration outside ended. But he said there were no damages to the bar or injuries.

"It definitely wasn't a large brawl. We don't think there were more than three people involved," Dickinson said.

Anyone with information may call Sgt. Thomas Piccicini at 856-488-0080, Ext. 2106.

Contact staff writer Darran Simon at 856-779-3829 or dsimon@phillynews.com.