A 16-year-old girl was arrested in connection with an assault that occurred in Waikiki over a year ago.

Police said that a man, 54, witnessed the suspect assaulting an unknown elderly man on Kalakaua Avenue about 12:50 a.m. on April 27, 2010. When the younger man tried to intervene, the suspect began assaulting him, police said. The victim sustained undisclosed substantial but not serious injuries.

The teenager was identified and arrested Thursday night on suspicion of second-degree assault.