FBI agents and police turned the entire village of of Armada, Michigan into a checkpoint last night, interrogating every driver who attempted to enter or leave the town and then marking ones who had been grilled with an ‘X’ on their hand.

Authorities took a blanket approach to the search for clues about 14-year-old April Millsap, who was found murdered in a wooded area last week.

With Michigan state police complaining about the fact that tips in the case have “dried up,” officers and agents occupied areas of the town between 5pm and 8pm last night, blocking off the main road and other routes before going “car by car” and quizzing every driver.

Pictures from ABC 7 showed huge tailbacks with cars “backed up for miles.” Armada township Police Chief Howard Smith defended the action, saying it was a necessary measure to find clues about the case by stopping cars driving in the vicinity of where the murder took place at the same time.

“It looked like a roadblock, but it was what police call a rolling canvas,” reported Local 4 News, adding that “swarms of police” covered three checkpoints.

A local group protested the move, asserting that the roadblock was unconstitutional and not backed up by probable cause. The group, which was not named in the ABC 7 report, planned to read both the federal and state constitution to the police chief.

“This is the second time in recent years that police have imposed what amounts to an mass investigative detention as part of a crime investigation,” writes William Norman Grigg, pointing to a similar approach after a June 2012 bank robbery in in Aurora, Colorado where everyone within the vicinity of the bank was placed in handcuffs.