An 18 year old Frederick man was arrested early Tuesday morning after he broke into his ex-girlfriend's Hagerstown house.

Just before 3 a.m. Libni Hernandez cut the window screen of the victim's home in the 700 block of Park Lane and went inside. He began arguing with her, pulled a knife out and groped her in a sexual manner.

The victim's family arrived and held down Hernandez until police arrived.

He was handcuffed and charged with burglary, assault, sexual offense, malicious destruction of property and reckless endangerment.