Maricopa County Sheriff’s Office Detective Brian Mackiewicz only testified for 15 minutes late Tuesday afternoon in the contempt of court case against Sheriff Joe Arpaio, but it was long enough to reveal that he might consider invoking his Fifth Amendment rights later in his testimony.

As Mackiewicz approached the stand around 4:45 p.m. on Tuesday, plaintiffs’ lawyer Michelle Morin said she noticed Mackiewicz’s lawyer pass him a note. Morin asked Mackiewicz to read the note in open court.

One of the reminders on the note was “Fifth Amendment invocation,” Mackiewicz said. The Fifth Amendment grants the right to not self-incriminate, and can be invoked to avoid answering certain questions.

Mackiewicz’s testimony in this case could be revealing since he is likely the MCSO employee with the most knowledge of the sheriff’s mysterious “Seattle Investigation.”

Mackiewicz worked closely with the sheriff’s now-discredited confidential informant in Seattle, Dennis Montgomery. Montgomery calls himself a CIA and National Security Agency whistleblower. According to court testimony, Montgomery claimed he had taken records from the CIA that proved a bank hacking conspiracy impacting tens of thousands of Maricopa County residents. 

Arpaio and his chief deputy both testified they no longer believe Montgomery is credible. A number of high-profile media reports have accused Montgomery of defrauding the Bush administration with bogus counterterrorism software, though Montgomery has publicly denied those allegations.

The sheriff’s office assigned Mackiewicz along with Sergeant Travis Anglin and volunteer posse member, Mike Zullo, to work with Montgomery on the bank fraud investigation in late 2013.

Zullo heads up the sheriff’s volunteer Cold Case posse and has worked on Arpaio’s pet projects, including the investigation of President Barack Obama’s birth certificate. Mackiewicz also traveled to Hawaii as part of that investigation.

Over the course of this contempt hearing, evidence has come to light suggesting Montgomery also was trying to link the federal judge in this case in a false anti-Arpaio conspiracy with the U.S. Department of Justice and plaintiffs’ lawyers. Montgomery created flowcharts and timelines suggesting illicit communications between those parties.

But Arpaio has adamantly denied in his testimony that the judge, U.S. District Court Judge Murray Snow, was ever investigated. At one point Arpaio said he believed Snow was connected to Montgomery’s investigation because he was on the list of alleged bank fraud victims.

On the other hand, plaintiffs are trying to argue Montgomery’s charts about Snow could suggest the sheriff was exploring ways to get Snow disqualified from the case, since in 2013 Snow ruled Arpaio had racially profiled Latino drivers and ordered sweeping changes at the agency.

During Mackiewicz’s brief testimony Tuesday, he began to testify about the link between Snow and the Montgomery bank fraud investigation.

He said that Zullo first had the idea of looking up the name of the judge who had ruled against the sheriff in the racial profiling case, since none of them remembered the judge was named Murray Snow. Then, according to Mackiewicz, they found Snow’s name on Montgomery’s list of alleged bank fraud victims.

Zullo is the other person with the most knowledge of Montgomery’s investigation, but his testimony has been postponed until he finds an attorney. Zullo is resisting turning over all his documents about Montgomery’s investigation to plaintiffs, and he is trying to invoke both the Fifth Amendment and the Fourth Amendment — which protects against unreasonable search and seizure.

Snow said he does not believe the Fifth Amendment can apply to civil document production, but he has given Zullo until Thursday to file a motion explaining his position.   

On Tuesday one of the county’s lawyers revealed the U.S. Attorney’s office had refused to grant Zullo immunity from criminal prosecution should his testimony be incriminating. 

If Montgomery took classified records from the CIA, that would mean he committed federal crimes. And even if Montgomery was lying about the origin of his records, there be legal implications for sheriff's personnel if they sought out Montgomery's data believing it to be stolen, classified records from the CIA.

Meanwhile, Mackiewicz is currently under a criminal investigation, though the details are not yet public.

Earlier in the contempt hearing it was revealed that Mackiewicz’s ex-girlfriend, a Maricopa County prosecutor, had alleged to MCSO internal affairs investigators that Mackiewicz was fraudulently reporting his overtime and had a relationship with a domestic violence victim from a case he investigated.

Updated 10/27/2015 at 10:22 p.m.