The victim, 25-year-old Johnika Tiggett, was found with a gunshot wound to the head around 1:30 a.m. Friday in the 2000 block of Dennie Street.
Police say there was an argument inside a bar near that location, which spilled out onto the street.
According to investigators, Tiggett tried to stop the fight as gunfire broke out.
She was hit in the hail of gunfired. Police say 41 pieces of ballistic evidence were recovered at the scene.
Tiggett was rushed to the hospital but was pronounced dead at 11:26 p.m.
The man police are looking for is 23-year-old Terrell Antwon of the 4400 block of N. Cleveland Street. The four men already in custody are:
Byron McDonald 19 years old from the 3100 block of N 25th Street
Anthony Palmer 33 year old male from the 5100 block of Reno Street
Roland Thompson 36 year old male from the 2400 block of W Toronto Street
Rashon Wiggins 24 year old male from the 1800 block of W Juniata Street
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through phillypolice.com.