A D.C. police officer who volunteers at a health spa in Northwest Washington was arrested Thursday and charged with sexually abusing a woman during a treatment session, according to police and court documents.

An arrest affidavit filed in Superior Court says the woman also is a D.C. police officer. Authorities said the officers, both assigned to the 4th District Station, were off duty at the time of the incident.

Police said officer Pearce Then, 42, of Adelphi, Md., is charged with one count of first-degree sexual abuse. Then, a veteran of the force for nearly seven years, has been suspended.

“Officer Then’s actions are a disgrace to everyone who wears a badge,” D.C. Police Chief Peter Newsham said in a statement.

Then’s attorney entered a not guilty plea in Superior Court on Thursday and a judge freed him pending a preliminary hearing July 8. He was put on high intensity supervision and ordered to stay away from the woman.

Then declined to comment when reached by phone. Police said in the affidavit that Then told detectives his actions were accidental.

Court documents say Then’s wife owns the health center, Roche’s Microblading & Spa in the 3600 block of 16th Street NW. The court papers describe Then as a volunteer.

The affidavit says Then and the female officer had been discussing a treatment and that she agreed to come to the spa on Monday.

The woman told police she was sexually abused during the procedure and that she reported the incident to her department superiors.