Nicholas Roske, 26, pleaded not guilty Wednesday to one count of attempting to kill a justice of the United States, two weeks after he was arrested outside the home of Supreme Court Justice Brett Kavanugh's home with a gun.
He faces a maximum sentence of life in prison.
Roske was arrested in the early morning hours of June 8 near Kavanaugh's Maryland home. He was allegedly armed with a gun and pepper spray, and had zip ties and several pieces of burglary equipment in a backpack, according to an arrest affidavit.
"Roske indicated that he believed the Justice that he intended to kill would side with Second Amendment decisions that would loosen gun control laws," the affidavit said. "Roske stated that he'd been thinking about how to give his life a purpose and decided he would kill the Supreme Court Justice after finding the Justice's Montgomery County address on the internet."
Last week, he was indicted by a federal grand jury on one count of attempting to kill a justice of the United States.
Dressed in a burgundy pants, a shirt and unmasked, Roske rocked back and forth silently in his chair as he awaited court proceedings. After pleading guilty, Roske at times rested his head on the table with his hands folded around the back of his neck.
Roske will face a jury trial before Magistrate Judge Ajmel Ahsen Quereshi on Aug. 23.
ABC News' Luke Barr and Alexander Mallin contributed to this report.