A Wisconsin teenager has been charged in the killing of his mother and stepfather in what the federal authorities described as an attempt to obtain the money and autonomy he believed was necessary for a plot to kill President Trump and overthrow the government.

The teenager, Nikita Casap, 17, was arrested last month in the deaths of his mother, Tatiana Casap, 35, and stepfather, Donald Mayer, 51, according to the Waukesha County Sheriff’s Department.

Sheriff’s deputies found the bodies at the family’s home in Waukesha, about 17 miles southwest of Milwaukee, after receiving a call on Feb. 28 requesting a welfare check, the department said.

According to federal documents unsealed on Friday, the fatal shootings were part of a plan by Mr. Casap, who identified with a right-wing terrorist network known as the Order of Nine Angles, to assassinate President Trump in what he believed would “foment a political revolution in the United States,” federal investigators said.

Mr. Casap also paid, at least in part, for a drone and explosives that he planned to use in an attack, according to the documents, which were filed in the U.S. District Court for the Eastern District of Wisconsin.

Mr. Casap’s lawyers could not be immediately reached on Sunday for comment.

A self-described “manifesto,” found on Mr. Casap’s phone and detailed in the federal documents, contained images and praise of Adolf Hitler, as well as instructions to others to make bombs.