A 71-year-old man accused of injuring a sheriff's deputy after shooting at a drug patrol helicopter as it flew over his rural northern Minnesota property Monday now faces federal charges.

Carstie Lee Clausen, of Clearbrook, Minn., was charged in U.S. District Court late Tuesday with assaulting an agent, damaging a federal aircraft and firing a gun during a violent crime. He's being held in the Clearwater County jail in lieu of $150,000 bail.

Clausen was charged earlier this week in state court in connection with the shooting, which injured Minnesota State Pine to Prairie Task Force special agent Brandon Larson.

It wasn't clear Wednesday when he would make his next court appearance.

Investigators who rushed to the Clausen residence after the shooting found him alone on the property. He told them he saw the helicopter flying overhead and on its first past made pistols out of his fingers and pointed them at the helicopter. On its second pass, he pointed a rake and hoe at the helicopter. He said he then grabbed his rifle and pointed it at the helicopter on its third pass.

Clausen told the investigators it was law enforcement's job to figure out whether he had shot at the helicopter. Agents searched the property and found the loaded rifle as well as an empty cartridge. They also found numerous marijuana plants.