An alert security guard helped police capture a 19-year-old man who allegedly snatched a woman’s purse in Waikiki in April, police said. 

Police said the incident happened about 5 a.m. April 3 as the woman was sitting on a bench with her purse hanging from her arm. 

The man allegedly grabbed the purse and fled. 

The security guard saw the man run away and was able to identify him. 

The alleged assailant, an inmate at the Oahu Community Correctional Center, was arrested at 9:15 a.m.  Aug. 2, for investigation of second-degree theft. The purse snatcher was charged Thursday with second-degree theft and his bail was set at $20,000.