A California man accused of attempting to assassinate President Donald Trump at a high-profile White House event entered a not guilty plea Monday, setting the stage for what promises to be a contentious legal battle.

Cole Allen, 31, faced a federal judge in Washington as his attorney entered the plea on all four counts related to the shooting at last month’s White House Correspondents’ Association dinner.

During the brief hearing, Allen sat silently in an orange jumpsuit, shackled at the wrists and ankles. U.S. District Judge Trevor McFadden advised Allen of a new grand jury indictment filed in the case.

The defendant’s legal team has already signaled an aggressive defense strategy. Allen’s federal public defenders are demanding that U.S. Attorney Jeanine Pirro recuse herself from the prosecution, arguing her friendship with the president and her presence at the gala where shots rang out creates a conflict of interest. The defense has also called for the removal of another top Justice Department official from the case.

Allen, who remains in federal custody, is scheduled to appear in court again on June 29. The attempted assassination unfolded during the prestigious dinner gala, an event typically attended by journalists and political figures. Surveillance footage from the shooting has already been made public as the investigation continues.

The case has drawn intense scrutiny given its high-profile nature and the questions it raises about security at major Washington events.