Ryan Routh, the man accused of attempting to assassinate Donald Trump while he played golf in South Florida last year, began his federal trial in Fort Pierce on Monday by addressing potential jurors and apologizing for bringing them in.

Representing himself, Routh wore a gray sports coat and red-striped tie as jury selection started under U.S. District Judge Aileen Cannon, who allowed him to proceed without an attorney but kept standby counsel.

Cannon dismissed Routh’s proposed jury questions as irrelevant but approved most from prosecutors.

Out of 120 potential jurors, 20 were excused for hardships, with the rest continuing questioning Tuesday.

Jury selection is expected to take three days, with opening statements set for Thursday, the Associated Press has reported.

Routh, 59, has pleaded not guilty to charges including attempting to assassinate a presidential candidate and assaulting a federal officer.

The trial is expected to last up to four weeks.