PROVIDENCE, R.I. (WPRI) — The R.I. Supreme Court on Thursday dealt a major blow to a criminal case against members of two biker gangs, agreeing with a lower case that key evidence must be suppressed after authorizations for wiretaps were improperly approved.

The case involves Deric “Tuna” McGuire, who police identified as the head of the Pagan motorcycle gang, along with dozens of other defendants that are together facing hundreds of drug and gun counts.

Attorney General Peter Neronha’s office will now “reevaluate the cases” in light of the ruling, spokesperson Blake Collins said.

“Today’s decision in this important case for public safety is a disappointment to this office,” Collins said.

At issue in the case is who signs off on the paperwork that allows investigators to secretly listen in on phone conversations. By law, only the presiding justice of the Superior Court is authorized to approve a wiretap — currently Alice Gibney — or the senior associate justice, if the presiding justice cannot do so.

Gibney did OK the original wiretap request from prosecutors, according to court documents, but later went on medical leave. She designated the task of signing off on further wiretap requests to Associate Justice Melanie Wilk Thunberg.

The senior associate justice is Robert Krause. McGuire and his co-defendants subsequently asked the court to suppress evidence obtained via the intercepted phone calls, arguing the wiretaps were signed by someone unauthorized to do so.

A Superior Court judge ruled in McGuire’s favor in 2019, and the AG’s office appealed the case to the R.I. Supreme Court.

The justices acknowledged that a different state law allows the presiding justice to “designate an associate justice to perform the duties” during an absence, which is what Gibney did when she designated the job to Thunberg.

But that law doesn’t supersede the wiretap statute, the Supreme Court concluded, which narrowly defines who can sign off on such orders.

“We continue to afford greater protection against intercepted wire, electronic, and oral communications because these seizures are more intrusive on personal privacy than the typical search warrant,” Associate Justice Maureen McKenna Goldberg wrote in the high court’s opinion released Thursday.

Despite the issues with the authorization, the AG’s office unsuccessfully argued the evidence obtained as a result of the wiretaps should be allowed to be be introduced at trial.

The Supreme Court justices said they had “no doubt” both the AG and the lower court justices acted in good faith, but “there simply was no statutory authority to designate an associate justice, other than the senior associate justice, to administer the orders arising from the wiretap investigation.”

McGuire’s criminal case is still awaiting trial. It’s unclear how much of the evidence in his case will now be tossed.

“In 2017, prosecutors seeking court authorization for a wiretap followed the direction of the Superior Court to the letter regarding which Superior Court justice they should seek approval from,” Collins said. “They did so in good faith and could take no other path in seeking such authorization. That said, we respect the Court’s decision and will reevaluate the cases in light of it.”

Tim White contributed to this report.