A man with a loaded gun in his car and a device in his underwear that would enable the firearm to act like a machine gun was arrested outside the Pentagon last week after attempting to speed off with Pentagon police officers clinging to his vehicle, according to court documents reviewed by CBS News. 

Prosecutors allege Kaleel Nagbe had a loaded firearm with 16 rounds, including one in the chamber, when he was stopped for a traffic infraction — holding a phone while driving — at the Pentagon complex. Prosecutors say the Pentagon police officer who stopped him smelled marijuana and subsequently ordered him out of his vehicle. Nagbe then jumped back into his car, and attempted to speed away, according to prosecutors. Justice Department court filings say “multiple officers hung onto the vehicle,” thwarting the suspect’s escape.

The court documents don’t allege Nagbe was planning to use the firearm at the Pentagon, but prosecutors said Nagbe injured an officer in a physical confrontation during the arrest. When he was stopped, Nagbe also had in his underwear a Glock switch, which would enable his semi-automatic firearm to become functionally fully automatic. 

In a separate court filing, the Justice Department said Nagbe, who has a criminal history including a prior firearms charge, had in his trunk 14 pounds of suspected marijuana. 

The injured police officer was treated at a nearby hospital for a hand injury. 

At first, a magistrate judge ordered Nagbe released on a personal recognizance bond, but the federal government urged the magistrate to keep Nagbe in custody, and he is now being detained pending trial.

Nagbe is scheduled to appear in federal court Wednesday afternoon in Alexandria, Virginia.

contributed to this report.