Prosecutors in a Brooklyn mob trial aren’t quite sure that jail guards can be trusted to keep their witnesses safe.

Eleven alleged mobsters and associates of the Bonanno crime family were charged last month with crimes ranging from attempted murder to arson conspiracy to loan sharking. The case is put together in part with help from two cooperating victims whose voices appear on 21 audio recordings. Defendants must review the recordings to prepare their defenses, but prosecutors said they worry the recordings may slip out of jail and endanger the victims’ lives.

At a hearing for Ronald Giallanzo, an alleged “acting captain” of the Bonanno family, and his associates, prosecutors said they did not trust corrections officers at scandal-plagued Metropolitan Correctional Center and Metropolitan Detention Center to safeguard the recordings.

“You would basically be relying on the jail to make sure [the CDs with recordings] come back,” Assistant United States Attorney Nicole M. Argentieri told Judge Dora Irizarry. She said it’s a risk too great when the cooperating victims “are at risk, given the nature of the case and these defendants.”

Instead, they insist the defendants should only be allowed to listen to the audios under the supervision of defense team staff.

The very jails that transported the defendants to a courtroom packed with friends and family on Monday can handle the audio evidence, defense attorneys said, though the judge remained skeptical.

“Oh its a problem. It is a problem,” Irizarry responded, adding that potential leaks wouldn’t be the first instance of correction officer corruption within the MCC and MDC.

“There are lots of levels of witness tampering,” she went on. “The concern is the ultimate level of witness tampering, where the witness dies.”

The two detention centers house individuals awaiting federal trial in New York, as well as some serving short prison sentences. Although guards are occasionally arrested for smuggling and corruption at the jails, they also host some of the world’s most notorious accused criminals, including Joaquín “El Chapo” Guzman. The top-security wing at MCC has been referred to as tougher than Guantanamo Bay by a man who’d been in both.

As part of a protective order in the Giallanzo case, attorneys and defendants will be prohibited from discussing what appears in discovery materials with other parties. All parties agree to that stipulation, but differ on whether the defendants should be allowed to access the audio files on their own in the law library. Many of their attorneys are solo practitioners who say they don’t have paralegals to send out to babysit in-jail listening sessions, and that the risk of audio leaks from CDs or hard drives is much lower than that of paper documents.

“To disseminate that would be very difficult. Each defendant gets stripped out every time they move,” said Joseph DiBenedetto, an attorney for Nicholas Festa.

“What would, no offense… what would prevent a paralegal from leaving a CD with a defendant?” Irizarry asked prosecutors.

“The answer is, nothing,” Argentieri responded.

But prosecutors insisted the extra layers of paperwork and screening would make the defense teams a safer bet.

“[Otherwise], you’re relying on those MDC guards to be perfect every time,” Argentieri said. “These lawyers, as officers of the court, and people who work for them, have a greater interest in career reputation and are less likely to put that on the line for one defendant.”

And although the defendants will know the identities of the cooperating witnesses after they listen to the audio, Argentieri insisted that the damage, should they choose to violate the protective order, will still be greater if they’re able to get the audio out.

“There’s a real difference between a defendant calling someone a cooperator, and being able to prove it by playing a tape,” the Argentieri said.

The AUSAs also requested that even the defendants out on bond be required to travel to their attorneys’ offices to review the materials with their attorneys, which defense lawyers said was too strict for men charged with non-violent crimes.

“Some of [the other defendants] have been charged with obstruction. Some of them have been charged with kidnapping. Some of them have been charged with attempted murder,” Irizarry said. “And that is concerning.”

The defense attorneys said their woes go far beyond whether the jails can be trusted to let their clients review the case against them. The MDC has disabled all audio on their computers and it may only be played on headphones, said Michael Hueston, an attorney for Michael Palmaccio.

But there’s a catch: There are no headphones available, Hueston said he was told.

“One impediment after another, to do something as simple as listen to a tape,” Hueston added, insisting the men have no incentive to interfere with the cooperating victims. “If they witness tamper, I’m sure the government is not shy, they will bring new charges,” Hueston said.

Irizarry is expected to rule on the matter shortly, but she didn’t seem fully convinced.