Legal experts are weighing in on actor Alec Baldwin’s potential defense strategies after charges of involuntary manslaughter were refiled against the 65-year-old actor by a New Mexico grand jury in connection to the fatal shooting of cinematographer Halyna Hutchins during a scene rehearsal on the set of Rust three years ago.

The charges against Baldwin, the lead actor and a co-producer of the ill-fated western, were dropped last April after “new facts” surfaced requiring further forensic analysis of the Italian-made “facsimile” of a Colt 1873 single-action revolver used in the shooting.

The new indictment – on similar charges that carry up to 18 months in prison if convicted – alleges that Baldwin caused Hutchins’ death either by negligence or “total disregard or indifference” for safety.

“I think it’s a weak case that they botched from the beginning, and Baldwin has unlimited resources,” said Neama Rahmani, a former federal prosecutor and president of West Coast Trial Lawyers. “Further, his maximum sentence here is 18 months, but his co-defendant got a no-time misdemeanor, so even if Baldwin is convicted, he’s going to get little to no time.”

Rahmani noted that prosecutors had gone to a grand jury to get an indictment instead of refiling their criminal complaint, thereby avoiding a preliminary hearing that, he said, “prosecutors had a real possibility of losing”.

Baldwin’s on-again, off-again prosecution centers on his part as both actor holding what was supposed to be a gun loaded with blanks and as a co-producer on the film with legal responsibility for safety on the production.

The actor said after the fatal shooting that “there are incidental accidents on film sets from time to time, but nothing like this. This is a one-in-a-trillion episode, a one-in-a-trillion event.”

Hutchins died aged 42 from her injuries at an Albuquerque hospital after being struck by a bullet that came from a gun held by Baldwin that subsequently wounded the film’s director, Joel Souza, after it exited her body.

The new, fourth-degree felony charge against Baldwin carries a sentence of 18 months. It rests on two theories: that Baldwin either caused Hutchins’ death as an “involuntary manslaughter by negligent use of a firearm”, or as involuntary manslaughter “without due caution or circumspection” – a charge that will require prosecutors to prove that Baldwin caused Hutchins’ death as “an act committed with total disregard or indifference for the safety of others”.

“We look forward to our day in court,” the actor’s attorneys, Luke Nikas and Alex Spiro, said in an email to the Santa Fe New Mexican.

According to legal experts, the indictment gives prosecutors an opportunity to win a conviction based on Baldwin’s obligations as a co-producer on the film.

“We don’t know exactly what their theory is,” John Day, a Santa Fe-based defense attorney and former prosecutor, told ABC News. “It could be that they’re including his role as basically CEO of the production … not having a safe workplace and somebody dies and you’re at the top of the pyramid.”

Rust Movie Productions, the company behind the film, paid a $100,000 fine to state workplace safety regulators after a report into safety failures included testimony that managers of the production took limited or no action after there were two earlier gun misfires on set.

The Santa Fe county sheriff, Adan Mendoza, noted soon after the accident that 500 rounds of ammunition – a mix of blanks, dummy rounds and suspected live rounds – were found.

The film resumed production in Montana last year, 18 months after it was halted following Hutchins’ death.

Rahmani said in an email to the Guardian that Baldwin’s advantage could be that “jurors love celebrities, and that’s why celebs are often acquitted at a higher percentage than other members of the public”, but also disadvantaged because “prosecutors also like to go after celebrities and make a name for themselves”.

The charges against Baldwin follow charges against Rust’s assistant director, David Halls, and the film’s armorer, Hannah Gutierrez-Reed. Halls pleaded no contest to a charge of negligent use of a deadly weapon in exchange for six months of probation. Gutierrez-Reed is scheduled to go to trial next month.

Court filings made public on Friday indicate that the Rust prop master, Sarah Zachry, has signed an agreement to cooperate with special prosecutors in return for leniency.

Los Angeles litigator and defense attorney Kate Mangels told ABC that Baldwin’s defense team will probably watch Gutierrez-Reed’s trial closely for clues to prosecutors’ strategy and the testimony of witnesses who are also likely to be called in their client’s case.

“It could offer a preview of the prosecution’s approach and potential witness testimony,” Mangels said.

It is believed Hutchins’ death was caused when live rounds and dummy ammunition were mixed up on the set. Baldwin initially claimed the gun had gone off after the pulled back the hammer but not the trigger, a claim that is subject to competing theories about the gun and its condition that now look set to be tested at trial.

In October, prosecutors looking at the case said additional facts had come to light that the state believed showed Baldwin could have “criminal culpability” in Hutchins’ death and Souza’s wounding.

Baldwin’s indictment, said Los Angeles attorney Miguel Custodio, “is one more factor that will accelerate the trend in Hollywood of phasing out real guns on set”.

Custodio predicted that whatever the outcome of Baldwin’s prosecution, insurance companies “will have to assess the risk of another tragedy if real guns are used on any set” and that the “public backlash from this case is making guns on sets less acceptable”.