A Defense Department contractor has been ordered to undergo alcohol rehab treatment after he was arrested and charged with making a threatening phone call to a Florida congresswoman.

Court documents say Darryl A. Varnum of Westminster, Maryland phoned the congresswoman's district office in late June and left a voice message that said, "I'm gonna kill your ass if you do that bill. I swear. I will f-----g come down and kill your f----g ass." The message continued in that fashion.

The call was an apparent reference to the congresswoman's co-sponsorship of the Vaccinate All Children Act, which would prevent states from receiving federal health service grants unless they require students in primary and secondary schools to be vaccinated.

The court documents say Varnum's wife reported to police in 2015 that he was having "behavioral issues," taking a rifle to the garage and yelling that ISIS fighters were coming to the house to fight him. He told responding police he'd been drinking vodka.

At a hearing July 10, a federal judge in Maryland ordered Varnum to complete a 28-day alcohol rehab program and seek mental health treatment before any further court proceedings.

Court documents do not identify the congresswoman.