A volunteer firefighter at both the Center Groton and Ledyard fire departments was arrested Friday on allegations that he inappropriately touched a 15-year-old girl.

Mark Stauffer, 36, was arraigned Monday at Superior Court in New London on charges of fourth-degree sexual assault and risk of injury to a minor. He remains in custody.

According to an arrest warrant, police were informed on Nov. 2 of the sexual misconduct when the victim's friend told her mother that her friend was being abused by someone the victim knows. The mother notified the Norwich Police Department, which made a referral to the state Department of Children and Families.

Ledyard police interviewed the victim and her mother on Nov. 2. The victim told police that Stauffer on numerous occasions inappropriately touched her, rubbed against her and behaved in other sexually inappropriate ways.

Police said they spoke to Stauffer on Nov. 3, and he admitted on numerous occasions to inappropriately touching the victim.

"He stated he does carry guilt about what he has done to the victim and wants help," the warrant said.

Center Groton Fire Chief Derek Fauntleroy and Ledyard Fire Chief John Doucette both said they were notified Monday by Ledyard Police of Stauffer's arrest and immediately placed him on administrative leave pending court action.

Fauntleroy said Stauffer joined the department in 2011 as a volunteer firefighter/EMT. He said Stauffer passed a thorough background investigation and reference check, which is required of all members. He noted, however, that since June, Stauffer has not been an active member.

Doucette said Stauffer joined the department in 2014 also as a volunteer firefighter/EMT. He, too, said Stauffer underwent background and reference checks.

Stauffer also was a volunteer at Ledyard Ambulance. Rick Mumenthaler, director of the organization, did not return calls for comment.

Stauffer is being held on $25,000 bond and was placed on a suicide watch. He has been ordered not to have any contact with the victim. His case was continued to Dec. 7.

i.larraneta@theday.com

Twitter:@larraneta