A 19-year-old man tried stealing a police officer's gun to kill GOP presidential contender Donald Trump during a weekend rally in Las Vegas, according to a federal complaint filed Monday.

The complaint, filed by the U.S. Attorney's office in Nevada, identified the would-be assassin as Michael Steven Sandford.

Sandford faces one count of attempting to commit an act of physical violence on restricted grounds.

Sandford, who has a United Kingdom driver's license, approached a Las Vegas police officer during a rally at the Treasure Island Casino pretending to ask for an autograph, the complaint says.

Authorities charged Sandford with trying to commit an act of violence against a person in a restricted area. He could be sentenced to up to 10 years in prison if convicted.