Police say they believe it started with a minor crash, possibly involving road rage, before it escalated to the deadly shooting.
Authorities released images of the suspect on Thursday afternoon. A $20,000 reward is being offered for a tip that leads to an arrest and conviction.
It happened just after midnight on Thursday at Pete's Pizza in the 2000 block of Ridge Avenue, next to Girard College.
Homicide investigators say they watched it all play out on video from multiple angles.
"The pizza takeout recorded some pretty clear images of our shooter and pretty clear images of the shooting," said Chief Inspector Scott Small, with the Philadelphia Police Department.
Police say the 26-year-old victim was driving a Honda when he got into a minor crash with another man and pulled over outside the pizza shop.
That's when the men started arguing and then went into the pizza shop, where they got into a fight.
Police say the gunman shot the victim in the head and then left the store in what is believed to be a dark-colored or black SUV.
"Homicide investigators will retrieve all the camera and recordings and, hopefully, we can get a license plate of the shooter's vehicle. But we also have a pretty good description of that shooter, with the shoulder-length dreadlocks that appear to be gray in color," Small said.
Employees at Pete's Pizza have dealt with a lot this year, including the deadly shooting of one of their pizza delivery drivers.
Danny Matthews, 29, was shot and killed outside the business back in June as he was returning from a delivery. In that shooting, police said robbery was the motive, however, the suspect didn't get away with any money before running from the scene. There has been no word on whether anyone was arrested in Matthews' case.
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