(BCN) – A man who was shot while attempting to help a robbery victim on New Year’s Eve at the Sunvalley Shopping Center in Concord has died at a hospital, police said Thursday.

The Contra Costa County Coroner’s Office has identified the victim as 32-year-old Calvin Crosby, a resident of Concord.

Concord police said in a statement they have arrested someone in connection with the killing, but said “the case is still under investigation, and we will not release any more information at this time.”

Police initially said the victim was trying to help a man who was being robbed inside the mall by multiple suspects, and they responded to a call on the mall’s lower level at 3:44 p.m. on Dec. 31.

Concord police are asking anyone with information regarding the case to contact Detective James Nielsen at (925) 603-5817 and refer to case number 21-12835.