Nearly three years after cinematographer Halyna Hutchins was shot and killed on the New Mexico set of the film “Rust,” Alec Baldwin is going on trial over her death. Here are the essential things to know.What charge does Alec Baldwin face?The actor is about to enter a New Mexico courtroom for the first time since the Oct. 21, 2021 shooting. He is charged with felony involuntary manslaughter. If a jury unanimously convicts him, he could get 18 months in prison.Baldwin, the star and co-producer of the Western, was pointing a revolver at Hutchins during a rehearsal in a small church on the movie set at Bonanza Creek Ranch when the gun went off, killing her and wounding director Joel Souza. Baldwin has said he pulled back the hammer — but not the trigger — and the gun fired.Two major themes will predominate, one large, one small: the chaotic atmosphere of the movie set, and the details of the Italian-made classic revolver that Baldwin pointed at Hutchins.It has never been officially determined who brought the live rounds that killed Hutchins on to the set. Prosecutors at the previous trial of “Rust” armorer Hannah Gutierrez-Reed alleged that she was responsible. She was convicted of involuntary manslaughter and sentenced to the same 18 months in prison Baldwin faces.What jurors must decideProsecutors have two alternative standards for proving the charge. One is based on the negligent use of a firearm. The other is proving beyond a reasonable doubt that Baldwin acted with total disregard or indifference for the safety of others.Despite the legal and technical complexities of the case, the 12 citizens of Santa Fe County that will make up the jury will have to reach just one verdict — guilty or not guilty — on a single count.How long is the Alec Baldwin trial expected to last?The trial at the First Judicial District Court of New Mexico — about 20 miles northeast of the movie set and the shooting — is projected to last nine days, and Judge Mary Marlowe Sommer insists that she’ll keep the lawyers in line and on schedule. Jury selection begins Tuesday, with opening statements expected Wednesday, and the projected end the following Friday. Once the jurors get the case, however, they can deliberate as long as needed.How will pretrial motions shape the case? Baldwin’s role as a producer of “Rust” isn’t relevant to the involuntary manslaughter trial over a fatal shooting on set, Sommer ruled Monday.The move was a major setback for prosecutors, who had planned to present evidence that showed how Baldwin bore a special responsibility — as co-producer, well beyond that of the actor holding the gun — for the dangerous environment that led to the deadly shooting.“I’m having real difficulty with the state’s position that they want to show that as a producer he didn’t follow guidelines and therefore as an actor Mr. Baldwin did all of these things wrong that resulted in the death of Ms. Hutchins because as a producer he allowed these things to happen,” Sommer said. “I’m denying evidence of his status as a producer.”Special prosecutor Erlinda Ocampo Johnson argued unsuccessfully that Baldwin was “keenly aware” of his safety obligations as a producer, in an attempt to bolster an alternative theory of guilt beyond negligent use of a firearm. The prosecution has tried to link Baldwin’s behavior on set to “total disregard or indifference for the safety of others.”In the courtroom Monday, Baldwin sat between lead attorneys Luke Nikas and Alex Spiro. He appeared to listen intently, taking occasional notes on a yellow legal pad and handing written messages to an attorney. Baldwin wore glasses and close-cropped hair. On Monday, the judge also sided with prosecutors to exclude at trial the summary findings from a state workplace safety investigation that places much of the blame on assistant director Dave Halls. Halls has pleaded no contest to negligent use of a firearm and may be called to testify at Baldwin’s trial.Prosecutors say the workplace safety investigation was incomplete, unreliable and glossed over Baldwin's responsibilities in the fatal shooting.Rust Movie Productions paid a $100,000 fine to resolve violations of state safety regulations that were characterized as “serious” but not willful, under a 2023 settlement agreement. Several witnesses to the workplace safety investigation are likely to be called to testify at Baldwin's trial.Why is Alec Baldwin famous?Baldwin, 66, emerged as a major movie star in the late 1980s and early ‘90s through films like “Beetlejuice” and “The Hunt for Red October,” and has remained a household name ever since. He would move on to memorable supporting roles in films including 2003’s “The Cooler,” which got him an Oscar nomination. Comedy dominated his later career as he won two Emmys for playing network executive Jack Donaghy on six seasons of “30 Rock,” and won a third for playing Donald Trump on “Saturday Night Live.”He has also played the role of outsized public personality, as a cherished talk-show guest, a sought-after liberal, and at times as a man unable to control his outbursts of anger, which have brought public embarrassment and a previous run-in with the law much more minor than the current one.Baldwin is the eldest of six children — five of them actors — from Massapequa, New York, who has lived in New York City for most of his adult life. He has an adult daughter, Ireland Baldwin, with his first wife Kim Basinger, and seven small children with his second wife, Hilaria Baldwin.Alec Baldwin's defenseBaldwin will bring with him an elite legal team of mostly New York-based attorneys, many of them Harvard Law graduates, from the firm of Quinn Emanuel Urquhart & Sullivan. Alex Spiro, a 41-year-old defense attorney who has represented Elon Musk, Megan Thee Stallion and other prominent figures and has become among the most sought-after lawyers in the country, will give aggressive cross-examination to the state's witnesses.The defense will try to show that it is not the job of an actor to make sure real rounds are not in his gun, a position strongly supported by Baldwin’s union, the Screen Actors Guild-American Federation of Television and Radio Artists.Baldwin said in an interview with ABC News, and implied in interviews with authorities, that he never pulled the revolver's trigger.His lawyers will also attack the gun evidence, and the serious damage done to the revolver during an FBI test they say amounted to the destruction of evidence and left the defense no chance to examine it.Firearms experts for the prosecution who testified at the Gutierrez-Reed trial are returning to the witness stand, over objections by Baldwin, to testify about his handling of the revolver and whether the gun was functioning properly.And they may press witnesses over whether Hutchins received proper medical treatment between the shooting and the declaration of her death at a hospital.Video below: Reaction from both sides on Hannah Gutierrez-Reed's sentencingThe prosecution teamSanta Fe County District Attorney Mary Carmack-Altwies appointed Kari Morrissey as a special prosecutor in the Baldwin case in early 2023 after her predecessor stepped down because of conflicts of interest. Morrissey promptly had the indictment against Baldwin dismissed, but revived it in January of this year by grand jury. Both moves came from further examination of the evidence, she said.Morrissey graduated from the University of New Mexico and its law school, and practiced law in Albuquerque for more than 20 years. New Mexico criminal defense attorney Erlinda Johnson joined Morrissey's team in April.The trial could bring a culture clash between the team of attorneys, as fiery hearings and filings have already shown.Morrissey and Spiro in particular have butted heads often — “I’m not going to sit here and be called a liar!" — she said during one such moment at a May hearing — and will likely do the same and provide some drama during the proceedings.The prosecutors will try to convince jurors that as a producer and the most important person on the set, Baldwin brought a recklessness to the production, and that as an actor he was negligent in handling his gun.Who's expected to testify at the Alec Baldwin trialThe crew members inside the small church building who became eye-witnesses to Hutchins' killing will provide the trial's most essential testimony. They include director Joel Souza, who was himself shot and wounded by the bullet from Baldwin's gun, and assistant director David Halls, the film's assistant director, who some said was responsible for the shooting but pleaded no contest to negligent handling of a firearm.Zac Sneesby, a crew member who was holding a boom microphone during the rehearsal, will testify that he saw Baldwin pull the trigger of the revolver, prosecutors said in court filings, making him potentially the most important witness of all.Prosecutors also may call Gutierrez-Reed to the stand, but Marlowe Sommer rejected an immunity deal they wanted to give her.Jurors will hear testimony from firearms experts who allege the revolver was working properly could not have fired without pulling the trigger.And Baldwin himself can take the stand in his defense, but he doesn't have to. His attorneys have not said which he will do.Where the ‘Rust’ shooting happenedSanta Fe, New Mexico's capital, an arts mecca of 89,000 people and a tourist destination for its historic Southwestern beauty, is no small town. And its downtown modern legal complex is hardly a country courthouse. But the location is still a far cry from the coastal urban courts where the celebrity trials of Bill Cosby, O.J. Simpson, Harvey Weinstein and Donald Trump were held.The proceedings could make for an unusual scene. Scores of members of the national media will compete for seats in the Santa Fe courtroom and an overflow room, and cameras will surround the courthouse for arrivals and departures.And the public can watch. The trial will be streamed and broadcast by several outlets including Court TV.Who is Halyna Hutchins?Hutchins, who was 42 when she died, was a cinematographer on the rise and a mother of a young son when she was killed. She grew up on a remote Soviet military base and worked on documentary films in Eastern Europe before studying film in Los Angeles and embarking on a promising movie-making career.