Lindsay Clancy does not deny that she killed her three children.

But she has nonetheless pleaded not guilty to murder, claiming that she was overmedicated and suffering from postpartum psychosis when she fatally strangled them, and thus not criminally responsible.

Because of the nature of her plea, a potential not guilty verdict would not mean she goes free. Instead, she would likely face an indefinite stay in a secure state mental health facility.

Daniel S. Medwed, a law professor at Northeastern University in Boston, tells PEOPLE that the Mᴀssachusetts law surrounding a lack-of-criminal-responsibility defense is complex.

“If a defendant is found not guilty by reason of insanity, the court enters an observation order,” Medwed says. “The person is then observed for up to 40 days.”

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At the end of the initial observation period, Medwed says, either the district attorney or whoever is in charge of the mental health facility can peтιтion the court for an initial commitment order of up to six months.

When the six months are up, there would be a review and the potential for another commitment order for another year, and the process could continue, according to Medwed.

“Then there might be another review and an order for a year, and so on,” he says. “It could go on indefinitely.”

The district attorney would also have a right to be notified about any upcoming review, which is typically conducted under the supervision of the superintendent of the facility or its medical director.

While the review could recommend that the person’s commitment order be rescinded, the ultimate decision is up to the court.

Regarding the lack of criminal responsibility defense itself, while the defense has to introduce evidence regarding the defendant’s mental state, the burden of proof is still on the prosecution, says Medwed.

“It’s on the prosecution to essentially refute [the defense’s evidence] and show that the defendant was criminally responsible,” Medwed says.Want to keep up with the latest crime coverage? Sign up for PEOPLE’s free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

Clancy is charged with the murders of her daughter Cora, 5, son Dawson, 3, and 8-month-old son Callan.

The children were found unresponsive by their father, Patrick, who first discovered his then-wife in the backyard after she jumped out of a second-story window.

Clancy’s trial is expected to last multiple weeks.