A Waterville man has pleaded not guilty to charges he broke into a 73-year-old woman's home and raped her at gunpoint.

The Morning Sentinel reports 32-year-old Mark Halle, of Waterville, entered the plea Thursday to charges of gross sexual assault, burglary and related offenses. He was arrested in February, soon after the woman reported the attack.

Authorities say Halle broke into the woman's home by removing a window air conditioning unit. Prosecutors say she was awakened by the noise and Halle forced her into a bedroom, put a pillow case over her head and sexually assaulted her.

Police found a pellet gun nearby and say they believe it was used in the attack.
Halle's bail has been set at $500,000. He's due back in court on June 1. (AP)