A good Samaritan came to the aid of a man at Ala Moana Beach Sunday afternoon who was being accosted by a homeless man who had allegedly tried to steal his cellphone.

Police said the 34-year-old suspect approached the 53-year-old man at the beach at 4:20 p.m. The suspect allegedly punched the man in the face and took his cellphone, police said. A witness came to the aid of the victim and the two men detained the suspect until police arrived.

The suspect was arrested on suspicion of second-degree robbery and six outstanding contempt warrants.