Biddeford Mayor Alan Casavant announced on Thursday that he has reached out to U.S. Attorney General Loretta Lynch for federal guidance on how to best investigate allegations that city police officers sexually abused young men years ago.

Casavant released the letter, dated July 6, to the media and also went on YouTube to explain in more detail why he asked the federal government for help.

“Normally I would give the (Maine) Attorney General the courtesy of allowing her to respond first, without announcing to the media that our correspondence is in progress,” Casavant said in a statement. “However, given the truly singular nature of events this week, I thought that those seeking justice for sexual abuse victims would appreciate knowing that a dialogue with the U.S. Department of Justice has begun.”

The mayor said he and city attorney Keith Jacques began contemplating the approach to federal authorities in April. They sought input from the office of Sen. Angus King, who advised the city to write directly to Lynch. As of Thursday, Lynch had not responded. Her office didn’t immediately respond to a request for comment Thursday afternoon.

Alleged abuse victims and their supporters claim that the city, its police department and the Maine Attorney General’s Office are incapable of conducting an impartial investigation. The tension between the city and those victims has led to outbursts and frequent disruptions during Biddeford City Council meetings.