Alec Baldwin’s involuntary manslaughter trial came to a dramatic end on Friday, after a New Mexico judge dismissed the case against the actor and found that the state had improperly withheld evidence related to how live rounds of ammunition ended up on the film set where the cinematographer Halyna Hutchins was fatally shot.

Just days after courtroom proceedings had begun, Judge Mary Marlowe Sommer ruled in favor of the defense and agreed that the charges against Baldwin should be dropped, finding that the state had concealed evidence that would have been favorable to the actor. The dismissal, made with prejudice, puts an end to the involuntary manslaughter case against Baldwin.

“The state’s willful withholding of information was intentional and deliberate,” Sommer said. “There is no way for the court to right this wrong.”

The news was met with relief from Baldwin, 66, who appeared to weep and hugged his attorneys and his wife, as the judge issued her ruling. Baldwin swiftly left court without making a statement to media.

The evidence in question was live rounds of ammunition turned over to New Mexico police in March, following the conviction of Hannah Gutierrez-Reed, the film’s armorer. That evidence suggested the live ammunition that made its way on to the set came from the prop supplier, rather than the film’s armorer, Baldwin’s attorney Alex Spiro said.

A witness confirmed to the judge on Friday afternoon that a special prosecutor in the case, Kari Morrissey, was directly involved in the decision to file the evidence in an entirely different case file separate from the other Rust materials.

The day had the twists and turns of a Hollywood drama as Morrissey’s role was revealed, another special prosecutor in the case resigned mid-day, and Morrissey took the stand herself. During her testimony, Baldwin’s defense attorney asked her whether she had referred to the actor as an “arrogant prick” and “cocksucker” in a conversation with a witness.

The dismissal brings to a sudden endthe criminal case against Baldwin over death of Hutchins on the Rust movie set. The 42-year-old cinematographer died after a gun Baldwin was holding during rehearsals fired a single live round of ammunition.

Prosecutors have long said evidence shows that Gutierrez-Reed, who was convicted of involuntary manslaughter in March, was the source of the live round, but the defense said the state had received evidence that suggested otherwise and “buried” it. A “good samaritan” had come forward to police this year with a box of munitions that he claimed came from the prop supplier, Seth Kenney, and matched the ammunition that killed Hutchins, Spiro had said on Thursday.

A report of that interview was not included with the other Rust evidence nor shared with the lawyer of Gutierrez-Reed, Spiro said. Testimony from Alexandria Hancock, with the Santa Fe county sheriff’s office, revealed that she and other officials made the decision to file it separately from the other Rust evidence in an entirely different case file.

Baldwin’s attorneys said the the report was relevant to the entire case and relevant to the credibility of witnesses who testified in the trial.

“If this evidence wasn’t as important as we say it is, they would have turned it over,” Nikas said.

In the morning, Morrissey had described the motion as a “wild goose chase” and said she had never before seen the report about the ammunition brought to the sheriff’s office. But as the judge questioned Hancock, the corporal said that Morrissey had taken part in the decision to keep the evidence separate from the Rust case – which elicited gasps in the courtroom.

Troy Teske, the man who came forward with the ammunition, is a friend of Gutierrez-Reed’s father, Morrissey had said earlier. She denied the defense’s accusations and said Baldwin’s team was aware of the evidence brought forward.

In a highly unusual move, Morrissey called herself to the stand to defend her conduct – despite instruction from the judge that she did not have to do so. “I was not aware at that point in time that it would not be linked to the Rust case number,” she said.

On cross-examination, Spiro asked Morrissey if she disliked Baldwin – which she denied – and if she had ever referred to the actor as an “arrogant prick” and “cocksucker” in a conversation with a witness.

She said she did not recall doing so.

“I actually really appreciate Mr Baldwin’s movies,” she said. “I really appreciated the acting he did on Saturday Night Live. And I actually really appreciate his politics.”

The developments upended the prosecution’s case and it was revealed during Morrissey’s testimony that the special prosecutor Erlinda Johnson had resigned in the middle of the day.

Baldwin could have faced 18 months in prison if convicted.