Drug busts at the border are common but Tuesday’s seizure of marijuana worth more than a million dollars stands out.

U.S. Customs and Border Protection agents, alerted by a one of their trained dogs, detected the drug in a tractor-trailer at the Otay Mesa cargo crossing, the agency announced Thursday.

The Freightliner truck was pulling a trailer that supposedly was empty. The agents inspected the vehicle with X-rays and discovered 412 packets of marijuana, weighing 865 pounds, with an estimated street value of $1.1 million.

The driver, a 48-year-old Tijuana man, was arrested and taken to the Metropolitan Correctional Center in downtown San Diego.