The shooting occurred around 1:45 a.m. at the intersection of Ross and Hortter Street.
Officers discovered a 28-year-old man sitting in the driver's seat of a Nissan Altima with a gunshot wound to the right side of his neck.
He was pronounced dead at the scene.
The passenger side of the vehicle was found open, police say.
So far, no word on a motive.
Police are searching for the suspect who fled the scene.
The victim's identity has not been released.