HOUSTON (KIAH) — A man is dead after a shooting in south Houston on Monday night, and police now have referred the incident to a grand jury.

It happened shortly before 11:30 p.m. at the 7900 block of Rockhill Street near Broadway Street.

Houston police say the incident started as an altercation, but it’s unclear what led to it.

Officers arrived and found a man with multiple gunshot wounds and was declared dead at the scene. Another man was on the scene and called 911 after the shooting, police said.

The man told detectives that was conducting a drug transaction with the victim when he attempted to rob him and another friend inside a vehicle. The shooter said the man shot at him and grazed his left cheek, then grabbed the gun from the man, got out of the car and tried to hold him at gunpoint.

But then the attempted robber charged at the witness with a knife, causing the man to shoot him multiple times, the man told police. The friend in the car was not injured.

The dead man is described to be a man in his late teens to early 20s.                

Detectives consulted with members of the Harris County District Attorney’s Office, who advised the incident would be referred to a grand jury.