NASHUA - A 28-year-old man is accused of sexually assaulting a teenage girl over a four-month period.

Police say Matthew Cousins, of 6 Locust St., Apt. 3, has been charged with seven counts of aggravated felonious sexual assault and six counts of misdemeanor sexual assault.

He was arrested on Monday and arraigned Tuesday at the 9th Circuit Nashua District Court.

On Dec. 4, authorities began investigating a report of numerous sexual assaults of a girl under age 16 at a city residence between August and November, according to police.

If convicted, Cousins could face up to 15 years on each felony charge.

He was being held on $25,000 cash or surety bail.