Police received a call about shots fired on Vassar Avenue around 2 a.m. Responders found the three men in the car on the residential street; two were already dead.
A neighbor said she heard six gunshots and saw bullet holes in the back window of the victims' Nissan Maxima.
Relatives identified the dead brothers as Fuquan Davis, 25, and Jalil Henry. The brothers' grandmother said their mother was "hysterical" over their deaths, and she couldn't imagine who would have wanted to hurt them.
The neighbor said Friday would have been Henry's 24th birthday. She also said all three victims were college graduates.
Police scoured shrubs and nearby yards for evidence. Several streets were closed down to assist the investigation.
The prosecutor's office confirmed the deaths of the men, but said its investigation into a possible motive was continuing.