Brown County Sheriff’s Department in Wisconsin used Flock cameras, which record the license plates of every vehicle that passes by them, to identify and arrest a resident of Wisconsin for purchasing marijuana. Per the report, the cops used Flock’s network of cameras to track the man as he drove from Wisconsin, where possession remains a misdemeanor punishable by up to six months in jail and a $1,000 fine for a first offense, to Michigan, where recreational weed purchase and possession are legal.

Per the report, the cops looked up his license plate and found that he “travels to Michigan frequently.” Of course, they couldn’t prove by the cameras alone that he was going to Michigan to buy weed. But apparently just going across state lines is enough to create suspicion. In a criminal complaint filed by the police against the man, they call Michigan a “known source state for marijuana as it is legal there.”