San Leandro police arrest man with clown mask, AR-15 in car

San Leandro police arrested a man during a traffic stop after they found an "It" clown mask and weapons in his car.

Police said they made the stop around 12:05 p.m. Sunday on eastbound I-580 at 150th Avenue in San Leandro. When they searched the car, they found a fully loaded AR-15, police said.

The AR-15, which had 50-round drum machine with one bullet in the chamber, was found concealed in a bag in the vehicle's backseat, San Leandro police said.

Police also recovered an "It" clown mask and marijuana from the vehicle.

Police did not state what originally made them pull over the car.

The suspect was arrested, transported to jail and booked on multiple drug and weapons violations, officials said. Police did not immediately identify the man they arrested. They also didn't immediately state whether he is part of some sort of political movement. 

"This was a great traffic stop that took an illegal and dangerous weapon off the street," San Leandro police wrote on Twitter. "This is another positive outcome in keeping the citizens of San Leandro safe."

KTVU contributed to this report.