A convicted Baltimore police detective testified Monday in the Gun Trace Task Force trial that he used to steal money with Sean Suiter, the city homicide detective whose fatal shooting in November — one day before he was to have testified before a federal grand jury in the case — remains unsolved.

The claim came on cross-examination of Detective Momodu Gondo, who admitted stealing from people dating to 2008. Defense attorney Christopher Nieto asked Gondo if he had told the FBI that he stole money when he worked with Suiter and a squad of several other people.

"You'd take money, split it among yourselves?" Nieto asked.

Gondo agreed.

Gondo is one of six gun task force officers to plead guilty in the case, and the last of four to testify for the government in the federal racketeering trial of Detectives Daniel Hersl and Marcus Taylor. His testimony, based on "proffer sessions" with the FBI last year in which he outlined allegations across the department in hopes of getting a lower sentence, implicated a number of other officers and supervisors as well.

The police department said on Monday that the "allegations and actions [are] disturbing, unacceptable, and criminal," and said Acting Commissioner Darryl De Sousa has formed a corruption investigation unit that will be led by a lieutenant colonel and specifically focus on the actions of the Gun Trace Task Force. The department has said previously that it had internal affairs investigations underway related to the case.

"We are working diligently to investigate and hold those who tarnished the badge and violated public trust accountable for their actions," police said in a statement. "The citizens deserve better and the hard-working honorable men and women of this agency deserve better."

Internal affairs investigations are kept under wraps in Maryland, which critics say helped at least some of the officers in the gun unit to avoid being held accountable for years as complaints stacked up.

Meanwhile, Deputy Commissioner Dean Palmere, who for years worked in and supervised plainclothes work, denied accusations that arose in court that he had coached officers on what to say after a fatal shooting in 2009. Palmere also disclosed that he is retiring, which he said he informed De Sousa about two weeks ago.

Monday's allegations revived the questions about the dormant investigation into Suiter's death. The detective was investigating a triple homicide in November when he was shot in the head with his own gun in a vacant lot in West Baltimore, police have said. His death was ruled a homicide by the medical examiner's office, and remains unsolved despite a $215,000 reward. Colleagues have said Suiter was an honest and beloved cop.

Suiter was shot one day before he was to have testified before a federal grand jury that was continuing to investigate claims involving the Gun Trace Task Force. Police have said that they do not believe there is a connection between Suiter's killing and his scheduled testimony, and the FBI declined a request by the former police commissioner to take over the investigation.

The Baltimore Sun has reported that there was internal tension, with some investigators believing that Suiter's death could be a suicide or an accident.

Sgt. Wayne Jenkins, the supervisor of the gun unit, was later hit with additional charges that he and Suiter had been involved in a 2010 incident in which drugs were planted on a man who fled and got into a serious crash. The indictment said Suiter did not know that the drugs had been planted, but had been the one who found them.

Umar Burley, who served years in federal prison after pleading guilty in the case, said after his conviction was overturned in December that the officers were masked and pointed guns at him, and that he thought he was being robbed. His attorneys say he made the accusation at the time he was charged.

Sherman "Pops" Basil, Suiter's 82-year-old uncle who helped raise him in Washington, dismissed the allegations against his nephew.

"Sean has never done anything wrong in his life," said Basil, noting that Suiter joined the Army right out of high school, served two tours and then joined the police force. "People will say anything, so I don't pay no attention to what they say."

Gondo was the final cooperating officer charged in the case to take the stand in the trial. It was Gondo's relationship with a Northeast Baltimore drug crew that first led investigators to the corrupt police unit. Gondo was picked up on a wiretap during a Drug Enforcement Administration investigation, which in 2015 was referred to the FBI to begin investigating the role of the officer. That expanded into an investigation into the Gun Trace Task Force, with a recording device being placed in one of its vehicles.

Palmere has been a deputy police commissioner since April 2015 and has been closely aligned with the agency's signature crime-fighting initiatives. Palmere told The Sun that he did not coach officers on what to say after a fatal shooting in 2009.

"It's not true. I would not coach somebody," Palmere said. "I've always taken pride in my ethics and integrity."

Gondo maintained that when he arrested someone for having a gun or drugs, it was always a good arrest. He said he never planted evidence or lied in search warrant affidavits.

— Baltimore Sun

Baltimore Sun reporters Kevin Rector and Alison Knezevich contributed to this report.