The mayor of College Park, Md., was arrested on Thursday and charged with possession and distribution of child sexual abuse imagery, the police said.
The mayor, Patrick L. Wojahn, 47, who had served in the position since 2015 and had been a member of the College Park City Council for eight years before that, submitted a letter of resignation after business hours on Wednesday night, city officials said.
He has been charged with 40 counts of possession of child exploitative material and 16 counts of distribution of child exploitative material, according to the Prince George’s County Police Department. He was in the custody of the county’s Department of Corrections, the police said.
College Park, which has 35,000 residents, is about seven miles northeast of Washington, D.C., and is home to the University of Maryland.
In his letter, dated Thursday, Mr. Wojahn wrote that it had been “a profound honor and privilege” to have served College Park and that he had cooperated fully with law enforcement officials and would continue to do so.
“While this investigation does not involve any official city business of any kind, it is in the best interests of our community that I step aside and not serve as a distraction,” Mr. Wojahn said, adding that he was resigning immediately.
“I am stepping away to deal with my own mental health,” he added.
The National Center for Missing and Exploited Children had notified the county police on Feb. 17 that a social media account operating in the county possessed and distributed what were suspected to be images of child sexual abuse, the police said.
Videos and an image had been uploaded to the account in January, and Prince George’s County Police investigators determined that the account belonged to Mr. Wojahn, the police said.
On Tuesday, detectives served a search warrant at Mr. Wojahn’s home, where they seized cellphones, a storage device, a tablet and a computer, the police said. After further investigation, the police charged Mr. Wojahn and took him into custody early Thursday morning, the police said.
Mr. Wojahn, a Democrat who grew up in Wisconsin, received his law degree from Georgetown University Law Center in 2002, and ran for mayor in 2015 “to help College Park realize its unfulfilled promise of becoming a top-tier college town,” according to his biography on the city’s website.
In addition to serving as mayor, Mr. Wojahn worked as the director of government relations for the Rails-to-Trails Conservancy, a nonprofit group that seeks to convert unused rail corridors into trails and to expand bicycle and pedestrian routes, the biography states. Rails-to-Trails Conservancy said in a statement that it had immediately placed Mr. Wojahn on leave.
Before joining that organization, he had been a policy and legal advocate for people with disabilities and for people living with H.I.V. and AIDS in the Washington area.
City officials said that Denise C. Mitchell, the mayor pro tem, would serve as the city’s presiding officer until a special election could be held and a new mayor sworn in. Under the city’s charter, a special election must be held within 65 days. The exact date will be chosen by College Park election officials.
“The City of College Park thanks Mayor Wojahn for his many years of dedicated service,” the city said in a statement.
Susan C. Beachy contributed research.