The head of a central Maine police department has resigned amid allegations he strangled the woman with whom he was having an affair. Dover-Foxcroft Police Chief Ryan Reardon delivered the news Friday via a one-sentence letter, declining to give a reason for his departure. He was charged with aggravated assault and criminal threatening with a dangerous weapon for allegedly choking his mistress during an August 23 argument, pointing a gun at her, twisting her arm above her head while she was on the ground, and covering her mouth to quiet her screams. He was placed on administrative leave following his arrest. The woman was not identified.