DERRY — Police arrested a Derry man on Thursday morning in connection with the robbery of an 18-year-old woman in MacGregor Park on March 21.

Michael J. Murphy was arrested on a warrant for robbery at his 2 Fenway St. address in Derry shortly before noon on March 29 and is being held on $20,000 cash bail at Rockingham County Jail pending an April 10 probable cause hearing, according to Derry police Capt. Vernon Thomas.

At 11 p.m. on March 21, police were notified by an 18-year-old woman that she had been robbed in the park.

“The woman stated that she had walked into the park with two male acquaintances,” said Thomas. “They talked briefly and then the men allegedly robbed her of her purse. The woman stated that one of the men produced a BB gun, pointed it at her head and forced her to hand over the purse which contained a large amount of cash.”

According to Thomas, the woman stated that the man made her get down on her knees and told her he would kill her if she contacted the police. Murphy and the second man allegedly fled on foot leaving the victim unharmed in park.

“The woman provided the name of one of the men as Michael J. Murphy, a person known to her,” said Thomas. “She stated that he was the one who pointed the gun at her and threatened her. Detectives investigated the incident and obtained a warrant for Murphy for robbery.”

Murphy was arrested without incident shortly before noon on Thursday. Detectives continue to investigate, according to Thomas.