A slew of Worcester County drug cases will be retried after a judge ruled that “egregious” conduct in the form of secret recordings made by Massachusetts State Police tainted the cases and denied defendants’ their right to pursue “vital defenses” at trial.

The order is yet another blow to an embattled agency that is still on damage control over the investigation of the Karen Read murder case in which lead investigator Trooper Michael Proctor, who made obscene comments about the defendant, was placed under internal review and eventually suspended without pay.

The affected cases, seven of which were directly referenced in the court order issued Monday, were part of a “sweep in the Fitchburg, Leominster and Gardner area” from January 2022 to April or May of 2022, according to the order by Fitchburg District Court First Justice Christopher P. LoConto.

During each case, MSP investigators made audio and video recordings, LoConto found, in violation of the state Wiretap Statute and failed to disclose the recordings to prosecutors.

“The court finds the MSP had actual knowledge that the recordings were made and being made, and they were aware of their obligations to turn said recordings over to the Worcester DA’s Office. The court also finds that certain financial incentives (promises, reward and inducements) given to the defendants, in the vast majority of cases, were not disclosed to the defense,” LoConto wrote in his order.

“The court further finds these violations to be egregious conduct that prevented the defendants from investigating and possibly implementing vital defenses that may have been available to each defendant,” Loconto continued. “For all of the above reasons, the court concludes that justice may not have been done in the above cases.”

LoConto recounts the cases of defendants Wilfredo Aponte, Shane Achilla, Ernest Charon III, Sheena Lynn Brooks, Michael Koziol, Nolan Montalvo and Adam St. Cyr, who all accepted plea deals in 2022 on various drug charges brought through the sweep.

Each of them received a letter from the Worcester District Attorney’s office on March 28, 2023, stating the existence of audio and video recordings from undercover drug buys that “were neither disclosed nor turned over to the defendants in this matter” as required by law, LoConto wrote. The defendants subsequently filed for new trials and the court stayed their sentences.

LoConto held three days worth of hearings on the matter in which he found that prosecutors only learned of the recordings on March 17, 2023, when the primary undercover operator, Trooper Paul Dunderdale, disclosed to one of them that a recording was available for an upcoming trial.

The prosecutor was shocked when Dunderdale informed her that most of the cases had been recorded, according to LoConto’s order, and reported it to her unit supervisor who started an investigation. LoConto “compliments” the prosecutors for the actions.

“This is in stark contrast to the actions of the MSP. This case represents a failure on the part of the MSP on many levels,” LoConto wrote. He further explained specific examples of failure at “the global level,” the “management level,” “the operational level,” and, finally, the “testimonial level.”

Both the Worcester DA’s office and the State Police told the Herald they are reviewing the decision.

Throughout the 34-page order, LoConto repeatedly said that he did not “credit,” nor find “credible,” much of the testimony of primary operation Troopers Dunderdale and Justin Burd, Sgt. Greg DesFosses — the leader of the Statewide Gang Unit at the time — or Det. Lt. David Crouse — at the time the leader of the MSP’s Technical Services Unit.

LoConto wrote that despite them testifying that either they were unaware of the recordings or that the recordings were made only for “officer safety” — which is a carve-out in the Wiretap Statute — there was significant evidence that the recordings were intentional and done outside of the legal parameters allowed in the investigations.

“The court would characterize much of the testimony by members of the MSP to have been a denial of responsibility, attempts to shift responsibility, an inability to recall salient details, parsed answers, and a general lack of acknowledgement as to the gravity of the situation,” LoConto wrote.