Seattle police are urging witnesses to a fatal shooting in Cal Anderson Park in March to share information about the shooter with detectives.

Police have not been able to locate a suspect in the March 20 shooting that resulted in the death of 21-year-old Hakeen Salahud-din, said Seattle police spokesman Detective Mark Jamieson. He said the police department released a video seeking information Thursday “to hopefully jog someone’s memory or appeal to somebody’s sense of justice for the family.”

Salahud-din was playing basketball in the park just before 10 p.m. when a fight broke out nearby. Police said he was shot after running over to protect his 17-year-old sister, who had been punched in the face by a man. Salahud-din died of a gunshot wound to the head, according to the King County Medical Examiner.

Salahud-din is survived by his longtime girlfriend and three daughters, one of whom was born this week, Jamieson said.

In the video, police said they knew that multiple witnesses, including some of Salahud-din’s friends, know the shooter’s identity. Police urged witnesses to share information with detectives by calling 206-684-5573, with the option to request confidentiality.

“Those who loved Hakeen and who considered him family know who did this to him. Remaining silent only protects his killer,” police said in the video. “If you were loyal to Hakeen in life, be loyal to him in death. Let his daughters know his life had value.”