Hill-Murray High School's head football coach, a member of the Mauer family, resigned Tuesday from his duties with the Catholic school in the wake his arrest in Fridley during a prostitution sting.

Mark Mauer, 54, of Woodbury, "resigned this afternoon" as coach and as a major-gifts officer for the Maplewood school, said Hill-Murray spokeswoman Sheri Lunn. Mauer was not a teacher there, Lunn added.

Mauer, 54, of Woodbury, was one of 19 men and four women arrested Tuesday in a two-day sting at the LivINN Hotel on Central Avenue NE., officials said. The women are charged with prostitution and the men with soliciting.

Mauer, a member of a St. Paul clan well-known for its athletic success — Minnesota Twins catcher Joe Mauer is his cousin — was named coach at Hill-Murray last year and served as a major-gifts officer at the school.

Police say Mauer arrived at the hotel Tuesday evening after making a date on the phone with an undercover officer, in response to an escort ad placed on an adult website. He agreed to pay her $100 for intercourse, then left the room to get the money and was arrested.

Mauer told police that he was just "messing around," that it was "stupid" to have gone there and that he had not intended to return when he left the room. Police said he was carrying Viagra pills.

In Mauer's first season last year at Hill-Murray, he coached the Pioneers to an 8-3 record and the state tournament, where they lost a Class 4A quarterfinal. He also was head coach at Concordia University in St. Paul from 2004 to 2010.

For a very brief time, Mauer was a St. Paul City Council member. After working as an aide to Council Member Dino Guerin, a childhood friend, Mauer was named to the council in 1997 when Guerin resigned to join the Ramsey County Board. A month later, he was offered a job as an assistant coach at North Dakota State University.

Mauer was a star quarterback at Harding High School in St. Paul and played football and baseball at the University of Nebraska. He has also worked as an assistant football coach at the University of Wisconsin and New Mexico State University.

This is the third time in recent years that a Hill-Murray employee has been accused of illegal sexual conduct. In 2010, former school president Joseph Peschges pleaded guilty to indecent conduct in connection with a police sting in a St. Paul park. Matthew Ricker, a former assistant boys basketball coach at Hill-Murray, pleaded guilty in 2007 to harassment for sending explicit messages to three players.

Star Tribune staff writer Kevin Duchschere contributed to this report. Paul Walsh • 612-673-4482