Gonzalez and his girlfriend, 23-year-old Caitlyn Jaje, were found dead late Sunday night in their apartment on the 1300 block of Federal Street.
Neighbors woke up to the police activity, stunned at what occurred.
"I looked out my window and saw the coroner," said Jesus Hernandez.
Homicide detectives and members of the Philadelphia Police Crime Scene Unit were on the scene for hours gathering evidence.
Police were called shortly after 11:45 p.m. Sunday for a report of a couple found unconscious.
"The two people were found by a family member who lives on the second floor," said Philadelphia Police Chief Inspector Scott Small. "They called police."
Gonzalez and Jaje were found lying on the floors of separate rooms.
Two found dead in apartment
Both were pronounced dead shortly before midnight.
There were no signs of forced entry, but police say they appeared to have been assaulted.
Sources say something was found around their necks.
"Both of the bodies have bruises to their face," Small said early Monday. "There was blood around both of their bodies. The property appears to have been ransacked."
Police have released no details about a motive or suspects.
The investigation continues.