A New Mexico judge dismissed involuntary manslaughter charges against actor Alec Baldwin on Friday after his lawyers alleged police hid evidence of the source of the live round that killed Rust cinematographer Halyna Hutchins in 2021.
Three days after Baldwin's trial began in New Mexico, Judge Mary Marlowe Sommer ruled after hearing evidence on the defence request made earlier on Friday.
The actor's lawyers said the Santa Fe sheriff's office took possession of live rounds as evidence in the case but failed to list them in the Rust investigation file or disclose their existence to defence lawyers.
They also alleged the rounds were evidence that the bullet that killed Ms Hutchins came from Seth Kenney, the movie's prop supplier.
Mr Kenney has denied supplying live ammunition to the production and has not been charged in the case. He had been expected to testify against Baldwin.
The actor was pointing a firearm at Ms Hutchins during a rehearsal for the Western film when the gun went off, killing her and wounding director Joel Souza.
The Colt .45 rounds at the centre of the dismissal were handed into the Santa Fe County Sheriff's Office on March 6 by Troy Teske, a friend of Thell Reed, the stepfather of Rust armourer Hannah Gutierrez, on the same day Ms Gutierrez was convicted of involuntary manslaughter for Ms Hutchins's death.
A Santa Fe County Sheriff's Office technician, Marissa Poppel, testified before the judge on Friday that the rounds were not hidden from Baldwin and she was told to file them and details on how they were obtained under a different case number to the Rust case.
She disputed the assertion that the Colt .45 ammunition matched the round that killed Ms Hutchins.
Prosecutor Kari Morrissey had questioned the allegation the evidence was concealed from Baldwin.
“If you buried it how did the defence attorneys know to cross examine you about it yesterday?” asked Ms Morrissey.
Prosecutors accused Ms Gutierrez of bringing the live rounds on to the set, an allegation she denied.
Prosecutors allege Baldwin played a role in the death of Ms Hutchins because he handled the gun irresponsibly.
His lawyers say Baldwin was failed by Ms Gutierrez and others responsible for safety on the set, and that law enforcement agents were more interested in prosecuting their client than finding the source of a live round that killed Ms Hutchins.