The judge overseeing Alec Baldwin’s involuntary manslaughter trial dismissed the case Friday after the actor’s lawyers accused the state of withholding evidence that could have been relevant to how live ammunition reached the set of the “Rust” movie, leading to the fatal shooting of its cinematographer.

After Baldwin’s lawyers called for dismissal of the case, Judge Mary Marlowe Sommer sent the jury home for the weekend, and the prosecution and defense began questioning witnesses who may have insight into the new evidence: rounds of ammunition that were turned in to police several months ago.

On Thursday, the defense revealed while questioning a crime scene technician that a retired police officer had turned in the rounds, which he thought to be linked to the “Rust” set.

Marlowe Sommer ordered that the rounds be brought into the courtroom, and she took the unusual step of getting up from her bench and examining the rounds herself.

The case revolves around the events of Oct. 21, 2021, when the gun Baldwin was rehearsing with discharged a live bullet that killed the cinematographer, Halyna Hutchins, and wounded the movie’s director. The weapon was supposed to have been loaded with inert rounds that could not fire.

The trial’s first three witnesses were members of law enforcement who responded to the fatal shooting. The jury saw footage of the chaotic moments when an on-set medic was tending to Hutchins.

The initial announcement that prosecutors were bringing a criminal case against Baldwin was met with shock from Hollywood, where many consider on-set gun safety the responsibility of a production’s weapons experts and safety coordinators, not its actors. (The movie’s armorer, Hannah Gutierrez-Reed, has already been convicted of involuntary manslaughter and sentenced to 18 months in prison.)

The case had put those Hollywood norms to the test and the conduct of Baldwin, a fixture of the television and movie industry for decades, under a microscope. The proceedings have been highly contested by his lawyers, who have argued for months that the prosecution was a misguided bid to secure a high-profile conviction of a celebrity. The prosecution argued that he was negligent in handling firearms.

The trial was expected to last about eight days at the Santa Fe County District Courthouse in New Mexico, where the proceedings were being livestreamed.

Why did prosecutors say he’s guilty?

The special prosecutors in charge of the case argued that Baldwin, 66, flouted industry rules about firearm use, citing industry guidelines that urge actors not to place their finger on the trigger of a gun before they are ready to shoot and never to point a weapon at anyone.

“He pointed the gun at another human being, cocked the hammer and pulled that trigger, in reckless disregard for Ms. Hutchins’ safety,” Erlinda O. Johnson, one of the special prosecutors, said in opening statements Wednesday.

Although those industry guidelines do not require that an actor independently check the gun on set, prosecutors argued that Baldwin had a responsibility to do so under the law.

The prosecution told the jurors that they would be presenting video footage showing that Baldwin was careless with gun safety on set. Johnson said the videos they planned to show include footage of him using his gun “as a pointer” on set and cocking the hammer of the gun when he was not supposed to.

They are also expected to argue at trial that just before the gun discharged a live bullet, Baldwin had failed to follow instructions from the director, Joel Souza, who has said that the particular take called for the actor to slowly pull the gun from its holster, not point the gun outward.

“You will hear the director tell you that many times, the defendant would do his own thing,” Johnson said in court.

What was the defense’s argument?

Baldwin, who was a lead actor and one of the producers on “Rust,” had pleaded not guilty to the manslaughter charge and had long denied responsibility for Hutchins’ death. Weeks after the shooting, he said in a television interview that Hutchins had been directing him where to point the gun and that the gun had discharged suddenly, without him pulling the trigger.

In opening statements Wednesday, Alex Spiro, one of Baldwin’s defense lawyers, argued that there were people on set responsible for safety, but that they did not include Baldwin. Gutierrez-Reed was in charge of checking the gun, as was Dave Halls, the film’s first assistant director, who has admitted that he failed to thoroughly inspect the gun and catch the live round.

“Everyone relied on them, and it was tragic that they let them down,” Spiro told the jury. “He was just acting as he has done for generations, and it was the safety apparatus that failed them all.”

The defense had tempered Baldwin’s vehement claim that he did not pull the trigger. Spiro said that even if he did, it is allowed on a movie set, especially when the actor was told that the gun was “cold,” meaning it should be impossible to fire.

“On a movie set, you’re allowed to pull the trigger,” Spiro said. “So even if — even if — he intentionally pulled the trigger like the prosecutor just demonstrated, that doesn’t make him guilty of homicide.”

To convict him of involuntary manslaughter, the jury had to find that the actor was aware of the risk caused by his conduct and ignored it. The defense argued that Baldwin could not have known the risk because it was unthinkable for live ammunition to end up on the “Rust” set.

Why was there live ammunition on a movie set?

Since the fatal shooting, the biggest mystery has been how live ammunition ended up mixed in with dummy rounds, inert cartridges that are used to resemble real ones for the camera.

Five other live rounds were found on set after the shooting, and prosecutors in Gutierrez-Reed’s trial argued that she was the one responsible for bringing them. The armorer’s lawyers denied that she was the source of the live rounds and are appealing her conviction.

In questioning the crime scene technician, the defense suggested that law enforcement did not properly investigate whether Seth Kenney, the movie’s primary supplier of guns and ammunition, could have been the source of the rounds, asking her why investigators waited more than a month to search his office.

At Gutierrez-Reed’s trial, Kenney denied being the source of the live rounds.

Why was the case dismissed?

Marlowe Sommer dismissed the case after finding that the state had withheld evidence that could have explained how live rounds ended up on the set.

During trial, Marlowe Sommer put on latex gloves to cut open a manila envelope of previously unexamined evidence that was brought into the courtroom. Lawyers for Baldwin accused the state of failing to disclose that it had been given a batch of rounds believed to be connected to the case when the defense asked to review all the ballistic evidence.

“They buried it,” Luke Nikas, a lawyer for Baldwin, said in court. “They put it under a different case with a different number.”

The New York Times News Service