A former University of Iowa medical-school student was sentenced to more than seven years in federal prison Wednesday for his plot to pay a hitman to murder one of his professors with a machine gun.

U.S. District Court Judge C.J. Williams sentenced Steven Arce, 36, of Waterloo, to 90 months in prison for his scheme to murder a UI College of Medicine professor after his expulsion from medical school.

Authorities said Arce admitted to selling an AR-15 rifle on Dec. 21, 2018, to another person known to have felony convictions. Arce asked if the person could murder one of his medical-school professors, according to a news release, but the person advised Arce to speak with someone more qualified.

During a Jan. 2 meeting, Arce sold a second gun to this person and the two arranged to meet with a hitman the next day. Authorities said the Waterloo man told the person with felony convictions that he was appealing his expulsion from medical school so he might want to delay killing the professor, instead saying he might want someone to beat the professor instead. Arce told the person that he was in possession of two automatic weapons that he could assemble.

Arce on Jan. 3 met with the hitman, who was actually an undercover law-enforcement officer. During the meeting, authorities said Arce told the officer that he wanted his girlfriend’s ex-boyfriend killed but might want the professor killed at a later time. As a down payment for the plot, Arce offered to give the hitman a machine gun.

While searching his Waterloo apartment, officers found two additional working guns and a box of gun parts.  An expert concluded that the parts could be assembled into a gun that could have fired in either semiautomatic or fully automatic modes.

Arce was sentenced to more than seven years in federal prison and must serve a three-year term of supervised release after his prison term. He is being held in the U.S. Marshal’s custody.

Assistant U.S. Attorney Anthony Morfitt prosecuted the case. The FBI, the Iowa Division of Narcotics Enforcement, and the Waterloo police investigated the matter.