A billboard along Interstate 94 is part of an effort to help catch a person who has been soiling slides at an Ypsilanti playground over the last six months.
Adams Outdoor Advertising put eye-catching messages such as "Help us flush the pooper" on an electronic billboard about the case.
Earlier this month, officials in Ypsilanti said they were taking measures to put a stop to the so-called mystery pooper. Police or other Ypsilanti employees have been stopping at Prospect Park each morning to make sure another surprise was not left overnight.
The park sits near a school and features a basketball court, a tennis court being used as a skateboarding venue as well as a picnic area.