Alec Baldwin 'Rust' shooting: what we still don't know about the case

Authorities investigating the movie set where Alec Baldwin accidentally shot and killed cinematographer Halyna Hutchins last Thursday have recovered 500 rounds of ammunition made up of a mix of blanks, dummies and suspected live rounds.

In its first official briefing since the incident, the Santa Fe County sheriff's office said there was “some complacency” in how weapons were handled on the set of Rust.

“Obviously I think the industry has had a record recently of being safe. I think there was some complacency on this set, and I think there are some safety issues that need to be addressed by the industry and possibly by the state of New Mexico,” Sheriff Adan Mendoza told a news conference on Wednesday.

While it has been determined that it was Baldwin who fired the suspected lead projectile that killed Hutchins, according to the sheriff, questions still remain on whether the projectile was a live round and, if so, why it was there on set.

Here are all the things we still don't know about the Rust shooting incident:

Did Alec Baldwin pull the trigger or did the gun just go off?

It’s still unclear whether Baldwin deliberately pulled the trigger or if the gun went off inadvertently. And if he did pull the trigger, who loaded the gun?

Entertainment trade website The Wrap reported that crew members had been using the weapons only hours before Hutchins was killed.

Dave Halls, the film's assistant director, handed the gun to Baldwin, telling him it was "cold" or safe. Baldwin, dressed in period garb as he played a wounded character named Harlan Rust, sat in a pew, working out how he would draw a Pietta Long Colt revolver across his body and aim it towards the movie camera.

The camera wasn’t rolling yet, but director Joel Souza peered over the shoulder of Hutchins to see what the camera saw. He then heard what sounded like a whip followed by a loud pop, he later told investigators.

Suddenly Hutchins was complaining about her stomach, grabbing her midsection and stumbling backwards, saying she couldn’t feel her legs. Souza saw that she was bloodied, and that he was bleeding, too. The lead from Baldwin’s gun had pierced Hutchins and reportedly embedded in his shoulder.

A medic began trying to save Hutchins as people streamed out of the building and called 911. Lighting specialist Serge Svetnoy said he held her as she was dying, her blood on his hands.

In the commotion after the shooting, Halls found the weapon – a black revolver manufactured by an Italian company that specialises in 19th century reproductions – on a church pew.

He brought it to armourer Hannah Gutierrez-Reed and told her to open it so he could see what was inside. There were at least four dummy bullet casings, with the small hole in the side, he told detectives.

There was one empty casing. It had no hole.

Sheriff Mendoza told reporters more questions were being asked of the people who inspected or handled the firearm before it got to Baldwin.

"We're going to try to determine exactly how that happened and if they should have known that there was a live round in that firearm."

Were there live rounds on set?

The FBI is helping out with ballistics analysis to determine whether or not the lead projectile that killed Hutchins was a live round.

Testing is being done to confirm whether the projectile taken from director Souza’s shoulder was fired from the same revolver used by Baldwin. Souza told investigators there should never be live rounds present near the scene.

Two other guns were seized, including a single-action revolver that may have been modified and a plastic gun that was described as a revolver, officials said.

“We suspect that there were other live rounds, but that’s up to the testing. But right now, we’re going to determine how those got there; why they were there because they shouldn’t have been,” Mendoza said.

Gutierrez-Reed said she checked dummy bullets on the day of the shooting to ensure that none were “hot” rounds. She also told a detective that while the guns used for filming were locked up during a crew lunch break, ammunition was left on a cart unsecured, according to a search warrant released on Wednesday ahead of the news conference.

Gutierrez-Reed told a detective that no live ammunition was ever kept on set.

Halls said Gutierrez-Reed typically opened the hatch of the gun and spun the drum, though he couldn’t recall if she did that before the shooting. He said he only remembered seeing three rounds in the gun, according to the search warrant.

Will there be criminal charges?

Santa Fe district attorney Mary Carmack-Altwies said on Wednesday they were not ruling out the possibility of filing criminal charges.

"All options are on the table ... No one has been ruled out at this point," she said at the press conference.

She also said that reports about assistant director Halls being fired from a previous production because of a gun safety violation might affect any eventual decision to prosecute.

"It obviously could play into whether charges get filed or not," she said.

Asked whether Baldwin – who also served as a producer on the movie – could face criminal charges, she said it was not out of the question.

Experts said criminal charges are possible, though probably not against Baldwin.

"For a criminal case, you're going to need some sort of actual intent, or criminal negligence, gross negligence. That's ... something more than pointing the gun," former federal prosecutor Neama Rahmani told news agency Reuters.

The criminal investigation is likely to focus instead on how the gun came to be loaded. "I think having live ballistic rounds on a movie set is inexcusable and rises to the level of gross negligence that you see in a criminal charge," lawyer Jeff Harris of Harris Lowry Manton told Reuters.

What about lawsuits?

The payouts arising from the legal fallout – which could be covered in part by insurance held by the film's production company – would probably be in the “millions and millions” of dollars, Adam Winkler, a professor at the UCLA School of Law and a gun policy expert, told news agency AP.

“There was clearly negligence on the set. The producers had a duty to preserve the safety of the crew. There were obvious hazards on the set."

Legal consultant Bryan Sullivan told news agency AFP: "I anticipate that everybody's going to be sued."

Baldwin is likely to be named in any lawsuit because of his deep pockets, and because his fame would help to draw media coverage, according to Sullivan.

"A plaintiff's lawyer would definitely want to name Alec Baldwin to get the money in there," Sullivan said.

The film's production company, Rust Movie Productions, has hired the law firm Jenner & Block to investigate the shooting. In a letter sent to cast and crew on Tuesday, the film's production team said Jenner & Block "will have full discretion about who to interview and any conclusions they draw".

– Additional reporting by AP, AFP and Reuters