Forty-five-year-old Frank Tepper is charged in the November 2009 slaying of 21-year-old William Panas Jr. in the Port Richmond section. The killing happened outside of Tepper's home - investigators say he left his daughter's baby shower after a melee erupted outside.
At one point, the jury asked to hear the 911 call again from that night.
"I discharged my firearm. I felt like I was assaulted," Tepper is heard to say.
The 911 dispatcher then asks "Are you a police officer?" to which Tepper is heard to reply "Yes I am."
Tepper's lawyer says his client was pummeled by more than six people when he tried to intervene and says he fired one shot because feared death or bodily harm.
The prosecution wants a first degree murder conviction, saying Tepper was not injured seriously and used deadly force against Panas because he was drunk and trigger happy - using his personal, semi-automatic pistol.
According to testimony, Panas was not one of the group that jumped Tepper.
Tepper's lawyer urged the jury to acquit the 16-year police veteran. Guilty verdicts could range from first degree murder, which carries a life sentence, down to "voluntary manslaughter - defined as 'a killing that occurs in the heat of emotion or a mistaken belief that it was self defense.'