Luigi Mangione scored a major legal victory on Tuesday with a judge dismissing the two top state charges against him: first-degree murder and second-degree murder, both of which prosecutors had argued were terrorism crimes.

Mangione still faces an additional second-degree murder charge, as well as a federal murder charge, in the killing of United HealthCare executive Brian Thompson last December.

The judge overseeing Mangione’s state criminal case, Gregory Carro, said “the evidence put forth was legally insufficient” for the two terrorism-related charges, in a written decision that was posted during a 15-minute proceeding in Manhattan court on Tuesday.

“Counts 1 and 2, charging defendant with Murder in the First Degree (in furtherance of an act of terrorism) and Murder in the Second Degree as a Crime of Terrorism, are dismissed as legally insufficient,” Carro wrote. “The People presented legally sufficient evidence of all other counts, including Murder in the Second Degree (intentional).”

Mangione also faces federal charges for allegedly gunning down Thompson outside a hotel, and weapons possession counts.

Mangione’s defense had also argued his case should be dismissed for double jeopardy – being prosecuted twice for the same crime – because he was charged with murder in both state and federal court, but the judge rejected that. He pointed to a supreme court decision stipulating that state and federal government are “two sovereigns”, and “where there are two sovereigns, there are two laws, and two offenses”. “Thus, there is no double jeopardy violation,” he wrote.

Carro also rejected the defense’s bid to put Mangione’s state case on hold so that he could face his federal trial first. Mangione’s team has contended that testifying in the state case could harm his defense in the federal death penalty trial, and claimed the timing could violate his right against self-incrimination.

Mangione entered the Manhattan courtroom just before 9.30am, wearing khaki jail scrubs, with handcuffed wrists and shackled ankles. His appearance came six days after the rightwing commentator Charlie Kirk was shot dead during an event at Utah Valley University. The shootings of Thompson and Kirk have prompted highly politicized rhetoric.

Although a motive in Kirk’s shooting remains unknown, conservatives have used the incident to call for the investigation of progressive political groups. Donald Trump has demanded the death penalty against the suspected Kirk shooter, Tyler Robinson, and his justice department is seeking the death penalty for Mangione.

The US attorney general, Pam Bondi, called Thompson’s killing “a premeditated, cold-blooded assassination that shocked America”. Bondi said her decision was in step with “Trump’s agenda to stop violent crime and make America safe again”.

The killing sparked a contentious public debate about US healthcare that crossed the political aisle, with some praising Mangione and denouncing healthcare companies and many others outraged that a murder would be used to air political grievances.

On Tuesday outside the 100 Centre Street courtroom, as with his prior court appearances, Mangione supporters gathered for a glimpse of him, lining up for courtroom seats and fanning themselves with yellow index cards that guaranteed entry. One woman wore a black T-shirt emblazoned with “FREE LUIGI” and another a white one reading “LUIGI’S PIZZA”.