Lindsay Clancy case headed back to court. Big news could be coming - USA Today

Lindsay Clancy's case will be back in court on Sept. 29, a key hearing that could mark a major turning point in the closely watched legal battle for the mother accused of killing her three young children.

Her first trial ended after a deadlocked jury couldn't unanimously agree on a verdict Sept. 4. Now, a court hearing could bring a sudden and dramatic end to the case — or another step toward a new trial.

Prosecutors are expected to reveal more about their plans to retry or drop the case. Meanwhile, the defense will urge the judge to find Clancy not guilty and to investigate a holdout juror.

Prosecutors alleged Clancy, 36, deliberately planned to kill her three young children at the family's Duxbury, Massachusetts home in January 2023. Clancy's defense team did not dispute that she fatally strangled 5-year-old Cora, 3-year-old Dawson and 8-month-old Callan, but argued that she should not be held criminally responsible because she was experiencing postpartum psychosis at the time, more commonly known as an insanity defense.

After weeks of testimony and 38 hours of deliberations, the jury remained split 11 to 1 on whether Clancy should be convicted of murder. Judge William Sullivan declared a mistrial Sept. 4 and ordered both sides to return to court at 9 a.m. local time on Sept. 29 for a status and trial assignment hearing.

Clancy's defense team has also asked the court to consider a motion to dismiss the case on double jeopardy grounds. Plymouth County District Attorney Timothy Cruz has not yet said whether he intends to retry Clancy for first-degree murder, for a lesser charge like manslaughter or forgo a second trial altogether, but that could also be addressed at the hearing, according to David Rossman, professor of law emeritus at Boston University. Cruz's office and Clancy's defense team did not respond to requests for comment from USA TODAY.

"I think it's likely that the DA's office will stick with the original charges just because he's that kind of prosecutor," said Rossman. "Timothy Cruz is not likely to seek an easier way out."

Sullivan set the Sept. 29 court date for arguments on one defense motion, and Clancy's defense has asked to present at least one more. One motion is calling for "a required finding of not guilty" and the other seeks more information about the holdout juror in the case.

Under Massachusetts law, a defendant can ask the court to find them not guilty on the basis that the evidence is insufficient for a conviction. It can be filed when evidence is completed, which defense attorney Kevin Reddington did in Clancy's case. If a judge denies the motion – as Sullivan did – it can be renewed within five days after the jury is discharged.

Reddington filed that renewed motion on Sept. 10, according to court records, arguing that the prosecution's evidence did not sufficiently prove Clancy understood what she did was wrong despite her serious mental illness. He said Clancy's actions around the time of the killings, which witnesses for the prosecution cited as the basis of their opinions, at best "show that Ms. Clancy could perform familiar tasks and act in sequence."

"They do not show that she could appreciate the wrongfulness or conform her conduct to the law," the motion said.

On Sept. 21, Clancy's defense team filed a separate motion arguing the charges against her should be dismissed altogether because the court failed to investigate the message from the jury that one juror wasn't following the judge's instructions on reasonable doubt.

Jurors, including the foreperson, have said the holdout juror expressed doubt about Clancy's guilt but refused to find her not guilty by lack of criminal responsibility. The juror, who has since publicly identified himself as Michael P. Desronvil, later disputed that characterization, saying in a statement released by his attorney that he "didn't have any doubts" and believed that Clancy "knew exactly what she was doing and planned."

As deliberations stalled, Reddington repeatedly pressed Sullivan to remove the holdout juror. Sullivan declined, saying that it wasn't appropriate for him to "agree with one juror or 11."

In order to declare a mistrial, there must be no other viable courses of action, but Clancy's attorneys argued the court did have another option: questioning and potentially removing the holdout. "Accordingly, any successive trial would constitute a violation of Ms. Clancy's Double Jeopardy rights," the motion said.

The filing does not specifically ask the court to consider the motion at the Sept. 29 hearing, so it is unclear when the judge may seek a response from prosecutors or issue a ruling. Rossman said if the judge rejects the defense's argument, Clancy's team has the right to appeal, which could push back a potential retrial date.

In a motion filed Sept. 18, Reddington requested that the holdout juror turn his phone over to a neutral examiner designated by the court as well as call and text message records from 8:30 a.m. to 4:30 p.m. on the deliberation days, according to a copy of the court filing. Juror #10, Nick Dargie, told ABC News following the mistrial that at times, the holdout wouldn't engage during deliberation and would "be scrolling on his phone while people were talking to him."

Reddington also requested the juror's confidential questionnaire and asked that prosecutors describe what background checks they ran on the jurors.

Reddington wants the court to question Desronvil about the truthfulness of the questionnaire and his answers during voir dire, a "sworn assurance" from Sept. 3 and the use of a cell phone or receipt of outside information during deliberations.

"The inquiry will not touch the substance of deliberations. The Court may also hear from Juror No. 10, limited to what he observed of Juror Doe's phone use," said the motion, which does not identify the jurors because Sullivan has impounded their names and questionnaires.

Reddington's filing requests the motion be heard at the hearing on Sept. 29. Desronvil's attorney, Edward Paltzik, called the motion "disgusting" in a statement released on social media.

"Reddington's motion is actually a full-frontal attack on the U.S. Constitution," Paltzik wrote. "Because if the new normal is that jurors are going to face brutal reprisals for disagreeing with a defense attorney, you can kiss the Sixth Amendment goodbye."

Unless there's reason to believe Desronvil was using his phone to get information about the case during deliberations, Rossman said it's highly unlikely the judge will allow the probe into his phone records.

"There's nothing there," Rossman said. "You can't attack a verdict or a mistrial on the grounds that there was a juror who was looking at the Red Sox score on his phone, or whatever he was doing."

The holdout juror has been at the center of intense speculation and faced criticism from his fellow jurors and Clancy's supporters. Paltzik has slammed those who have criticized Desronvil.

"Rest assured that the evil people who have so viciously attacked this American Hero and Champion of Justice will be held accountable to the maximum extent of the law and beyond," Paltzik said on social media.

Rossman said a juror receiving such negative attention and being forced to reveal private information in this way could hurt other defendants and discourage prospective jurors moving forward.

"I'm afraid it might make people more reluctant to be on a jury, especially people who think that their views might be in the minority," Rossman said.