LITTLE ROCK, Ark. — Police in Arkansas are investigating whether a man fatally shot himself in the head as he sat in the backseat of a patrol car with his hands cuffed behind his back.

Chavis Carter, 21, died after Jonesboro police stopped a truck in which he was riding July 28 and learned that he had an outstanding arrest warrant related to a drug charge. Carter was searched twice, handcuffed and put into the back of the patrol car, according to a police report.

Officers a short time later saw Carter slumped over in the backseat and covered in blood, according to the report, which concluded he had managed to conceal a handgun with which he shot himself. He later died at a hospital, and the report listed his death as a suicide.

Jonesboro Police Chief Michael Yates said Tuesday it appeared that Carter had shot himself in the head, but his department is investigating the incident.

“Specifically, how Carter suffered his apparently self-inflicted gunshot wound remains unexplained and investigation … continues given the unusual nature of this event,” the department said in a statement.

Yates said the department is working to reconstruct what happened, but is awaiting an autopsy report that could come as soon as this week.

Hundreds of people gathered in Jonesboro, about 130 miles northeast of Little Rock, on Monday for a candlelight vigil for Carter, and some questioned the circumstances surrounding the shooting. Some held signs asking “What really happened?” to Carter.

“Everyone wants justice,” Jonesboro resident Gale Taylor told The Jonesboro Sun after the vigil. “The circumstances are unusual, but everyone wants the truth.”

The National Association for the Advancement of Colored People also called for a thorough investigation into the death of Carter, who was black. The two other men who were in the truck with him and the two officers on the scene, Keith Baggett and Ron Marsh, are white, according to police.

“The public relies upon police to serve and protect all citizens, no matter their race or ethnicity,” the state conference and Craighead County branch of the NAACP said in a statement.

Baggett and Marsh are on paid leave while the investigation continues. FBI spokeswoman Kimberly Brunell said the agency is monitoring the case.