SAN DIEGO (AP) — A U.S. citizen has been charged in the smuggling deaths of three Chinese migrants who were found in the trunk of his BMW two days after he crossed the border, including a mother and her 15-year-old son.

Federal prosecutors say the bodies were discovered Aug. 11 when San Diego police got a 911 call from someone reporting a foul odor and blood dripping from the parked car.

Authorities say video recordings show 50-year-old Neil Edwin Valera driving into the United States at San Diego’s San Ysidro border crossing two days earlier. A witness said no one was seen coming or going from the parked car for two days.

Valera has pleaded not guilty. His attorney Jeremy Warren did not immediately respond to a request for comment late Tuesday.