Chapel Hill, N.C. — Chapel Hill Police Chief Brian Curran said Sunday a second person is believed to be in the photograph of a vehicle driven by a suspect sought in connection with the slaying of University of North Carolina at Chapel Hill Student Body President Eve Carson.

Photographs released during a news conference Saturday morning show what appears to be a person in the back seat of the vehicle.

The photos also show a black man who appears to be in his late teens or early 20s driving the vehicle. They were taken by a surveillance camera at an automated-teller machine, where the suspect used Carson's ATM card.

The sport utility vehicle shown in the photos might have been Carson's, police said. But Curran emphasized investigators did not definitively know if the vehicle belonged to the UNC senior.

A third photograph released shows a ball cap the suspect was thought to be wearing. It appeared to have a vintage Houston Astros logo on the front.

After the photos were released, photography expert William E. Mathis contacted The Raleigh Chronicle. Mathis wanted to color enhance a photo of the suspect in the hopes of assisting in the investigation. Mathis said he noticed a dark spot in the photo and determined that it was the shadow of another person in the vehicle.

Investigators still have no motive in the shooting death of the 22-year-old Athens, Ga., native and urge the public to call police at 919-968-2760 or Crime Stoppers at 919-942-7515 if they think they have information that might help.

Police said Sunday they have received a lot of leads in the case, but had not yet identified the man in the surveillance photos.

The University of North Carolina at Chapel Hill Board of Trustees is offering a $25,000 reward for information leading to an arrest in Carson's death.

Police continued to ask anyone who saw Carson's blue 2005 Toyota Highlander on Wednesday or Thursday to call them. The Highlander's Georgia license plate was AIV-6690.

“All conversations are confidential. Callers do not need to reveal their identity,” Curran said.

Officers believe the killer, at some point, had access to her SUV. It was found Thursday afternoon at North and Hillsborough streets, about a mile from the crime scene.

Carson’s body was discovered Wednesday morning on Hillcrest Circle, about a half-mile from campus.

A stolen-vehicle report said Carson had been shot at least once in the right temple. Police described the weapon as a handgun.