An Arizona man has been accused of assaulting a federal officer with a deadly weapon after authorities say he forced a National Guard convoy of COVID-19 vaccines off the road and held 11 members at gunpoint.

Larry Lee Harris, 66, of Willcox, Arizona, has been charged with assaulting a federal officer with a deadly weapon, federal prosecutors announced in a statement Friday. He already faced state charges of aggravated assault, unlawful restraint, impersonating a public servant, unlawfully carrying a weapon and interfering with military forces.

The incident occurred Monday northeast of Lubbock, Texas, where Harris drove his car into oncoming traffic to stop the convoy, according to police.

Officers say Harris believed the National Guard members had kidnapped a woman and a child and identified himself as a detective in an attempt to search the vans.

Harris is still pending an initial appearance in federal court. Conviction on the federal charge is punishable by up to 20 years in prison.