MINNEAPOLIS (AP) - Minneapolis Park Police have apologized for detaining and citing a Libertarian gubernatorial candidate who had gone to Lake Calhoun to gather petition signatures to get on the ballot.

An officer accused Chris Holbrook of violating a ban on using park land for commercial purposes. A video posted on his campaign website shows him being handcuffed and placed in the back of a Park Police squad car Thursday afternoon.

Park Police Chief Jason Ohotto apologized to Holbrook on Thursday night, saying he determined the arresting officer erred and misapplied the ordinance. He says the department has launched an internal investigation. The citation has been dismissed.

The department issued a statement saying the Park Board and Park Police understand and uphold the First Amendment freedom of speech in the parks.