The unidentified victim was punched and stomped on before being struck by a car, they said.
Detectives reportedly had trouble sorting out the fatality because it involved two events -- an assault followed.by a hit-run incident, according to a spokeswoman for Mercer County Prosecutor Angelo J. Onofri.
One suspect has been arrested in connection with the assault, Onofri said.
A second man from Central Jersey was arrested for allegedly driving over the pedestrian after he fell to the pavement, Onofri said.
Charges were based on eyewitness accounts and a review of surveillance video by Trenton police and county investigators, the prosecutor said on Wednesday.
Justin Wilkes, 21, of Ewing has been charged with first-degree aggravated manslaughter and endangering an injured victim, authorities said.
Wilkes is accused of punching the unidentified pedestrian and then stomping on him after he fell to the pavement, Onofri said.
At 11:10 p.m. Saturday, Trenton police were called to a report of a pedestrian struck at South Clinton and Roebling avenues, authorities said.
As police drove to the crash scene, they were told by a dispatcher that 9-1-1 callers had heard two gunshots.
An Hispanic man, who remained unidentified on Wednesday, was found laying in the street, Onofri said.
The victim was bleeding from his head and had visible tire marks across his torso, Onofri said.
Trenton EMS tried to help, but the victim was pronounced dead at the scene, Onofri said.
The Mercer County Medical Examiner initially determined the victim was run over by a car, significantly injuring the left side of his face, the prosecutor said.
Police have found no evidence of shots fired, Onofri said.
Area surveillance video was reviewed and eyewitnesses were interviewed, helping sort out two separate events, authorities said Wednesday.
Detectives believe that Justin Wilkes allegedly ran up to the victim and punched him in the head, Onofri said.
Wilkes continued to hit the victim as he tried to get away, Onofri said.
Wilkes then kicked and stomped on the man after he fell in the middle of South Clinton Avenue, Onofri said.
Wilkes reportedly fled by vehicle, leaving the beaten and unconscious victim on the pavement, according to Onofri.
Shortly after the assault, a white Honda Civic ran over the victim, witnesses told Trenton Homicide Task Force members.
Yuman allegedly kept driving, authorities said. Investigators were able to find the Honda and identified its driver as Elber Yuman, 24, of Princeton Junction, Onofri said.
On Sunday, Yuman was separately charged with "knowingly leaving the scene of an accident that resulted in death," Onofri said.
The victim remains unidentified.
Anyone with information is urged to call Homicide Task Force Detective Marc Masseroni at 609-989-6406.
Tips also can be emailed to mchtftips@mercercounty.org.
Click here to follow Daily Voice Middletown and receive free news updates.