Prosecutors say a man charged with murdering a Border Patrol agent by running him over with a drug-loaded Hummer escaped from custody three months earlier by fleeing to Mexico in a Border Patrol vehicle.

Jesus Navarro Montes was extradited from Mexico last week on a charge that he struck Border Patrol Agent Luis Aguilar in January 2008. The agent was laying down spike strips to stop him in southeast California's Imperial Sand Dunes.

The complaint says the Border Patrol detained Navarro Montes and an unnamed companion in September 2007 after their Toyota pickup got stuck in the sand. The companion allegedly took control of the Border Patrol vehicle and the pair drove it into Mexico.

Authorities found 979 pounds of marijuana in the pickup.