A Mattituck man was arrested and charged with engaging in a criminal sex act and sexually abusing a 12-year-old girl in the Smith Haven Mall, police said Monday.

Matthew McAvoy, 21, allegedly committed the sex act with the girl in a restroom corridor near the food court Saturday night, Suffolk County Police said.

Police arrested McAvoy Sunday and officially charged him with two felony counts of first degree criminal sex act and second degree sexual abuse.