PRISON 'BEAT-UP SQUAD' LEADER TESTIFIES AS ROBERT BROOKS’ MURDER TRIAL NEARS END
SGT. GLENN TROMBLY LED THE GROUP OF GUARDS THAT KILLED ROBERT BROOKS. PROSECUTORS CALL THE GROUP A 'GANG'
Glenn Trombly, a former New York State Corrections Sergeant, led the beat-up squad that killed Robert Brooks. He testified against three former members of the squad on trial for murder on Friday. Photo credit: New York State Department of Corrections and Community Supervision body-camera video via the New York Attorney General’s office.
UTICA, NEW YORK Oct. 14, 2025 Last updated: 6:07PM
The trial of three state prison guards for allegedly murdering Robert Brooks took a dramatic turn on Tuesday when their former supervisor testified against them.
The day ended with each of the three defendants declining to testify and their lawyers telling the presiding judge they wouldn’t be calling any defense witnesses at all.
Then-Sgt. Glenn Trombly led the beat-up squad that killed Brooks at the Marcy Correctional Facility on Dec. 9, 2024. He was responsible for supervising the infirmary and was inside the infirmary treatment room where the squad killed Brooks.
Trombly testified he also directed the attempted cover-up of Brooks' killing. He did it, he admitted,“To protect my officers.”
Mathew Galliher, David Kingsley and Nicholas Kieffer are three of the 12 former guards charged in connection with the killing.
"I told them they should get their stories straight," Trombly testified. "I directed them several times to make alterations to their reports to justify the injuries to Mr. Brooks.”
Trombly was wearing a body-camera the Department of Corrections and Community Supervision requires officers to wear. DOCCS policy, he testified, also requires officers to activate their cameras when they use force against a prisoner. But, Trombly admitted, he didn't turn his camera on when officers under his command beat and choked Brooks to death.
Trombly explained why: "I knew if I turned my camera on people would get in trouble."
In exchange for his testimony against Kingsley, Kieffer and Galliher, Special Prosecutor William F. Fitzpatrick promised Trombly a sentence of no greater than 4 years in prison for his plea of guilty to attempted gang assault.
Then-Sgt. Glenn Trombly led the beat-up squad that killed Robert Brooks at the Marcy Correctional Facility on Dec. 9, 2024. Photo credit: New York State Department of Corrections and Community Supervision body-camera video via the New York Attorney General’s office.
Brooks' killing was unintentionally captured on video by Trombly's body camera and body-cameras worn by three additional Marcy guards.
The Free Lance first reported the existence of Marcy's beat-up squad, and that it was led by Sgt. Trombly, days after Brooks was killed last December, Prison Guard 'Beat-Up Squad' Killed Robert Brooks, Operated for Years, Attorney General Letitia James's Office Knew it.
Special Prosecutor William F. Fitzpatrick called the group a "gang" during his opening statement to the jury when the trial started last Tuesday, The Free Lance reported.
"They were a gang," Fitzpatrick said. “They took turns— collectively and individually—of punching him, kneeing him, pepper spraying him, choking him, pinning him down, cuffing his legs.”
Beat-up squads were responsible for the deaths of Benjamin Van Zant at the Fishkill Correctional Facility in 2014 and Samuel Harrell, also at Fishkill, in 2015. No one was ever criminally prosecuted for either killing.
Former New York State Correction Officer Robert T. Kessler was a member of the beat-up squad that killed Robert Brooks. Here, body camera video captures his carrying an unconscious Brooks into the infirmary at the Marcy Correctional Facility where he was tortured and killed on Dec. 9, 2024. Photo credit: New York State Department of Corrections and Community Supervision body-camera video via the New York Attorney General’s office.
On Friday, former guard Robert T. Kessler also testified for the prosecution pursuant to a plea-bargain deal that promised him between five and seven years in exchange for that testimony.
Kessler testified Brooks shouldn't have been attacked.
"He wasn't doing anything at all," Kessler testified. "I was talking with the guy. I was working with him.”
Kessler also admitted to participating in the attempted cover-up.
"We had to create a narrative as to what happened," Kessler testified.
Trombly testified he ordered the guards including Kessler and the defendants on trial to re-write “Use of Force” reports they were required to file about the killing multiple times.
"I had to ask each officer to fix their reports two or three times," Trombly testified.
Cross-examined by Kieffer’s lawyer, David Longeretta, Trombly called Kessler a “hot head.” He also called Christopher Walrath “aggressive.” Kessler testified Walrath hit Brooks first, unleashing the group’s repeated assaults.
The 4-year sentence promised Trombly, and the 5-to-7 year sentence promised Kessler, in exchange for their testimony are significantly less than the 15-year and 22-year sentences handed down to other members of the beat-up squad who pleaded guilty but did not cooperate with the prosecution.
Anthony Farina and Nicholas Anzalone pleaded guilty to first degree manslaughter in exchange for promised sentences of 22 years in September. They will be sentenced Oct. 21.
Walrath admitted guilt to first degree manslaughter and was sentenced to 15 years in state prison Aug. 4.
Sgt. Michael Mashaw and guard David Walters pleaded guilty to second degree manslaughter for failing to stop the killing. Mashaw agreed to a 3-to-9 year sentence; Walters a 2 1/3-to-7 year sentence.
Nicholas Gentile was charged with evidence tampering. He pleaded guilty to a misdemeanor charge of attempted evidence tampering and was sentenced to one year conditional discharge and a $250 fine, the Rome Sentinel reported.
A twelfth guard accused of second-degree manslaughter, Michael Fisher, won a separate trial scheduled for January.
On Tuesday, Trombly pinned responsibility for Brooks’ killing on fellow former Sgt. Mashaw because, he said, Mashaw was responsible for supervising one of the three places where Brooks was assaulted.
“First it was going to be Sgt. Mashaw,” Trombly claimed, “because he owned the walkway.”
He explained that per prison policy, the supervisor of an area where an assault begins is responsible for supervising not just that assault but any additional assaults that follow on the same prisoner, wherever he is taken.
“I’m just there to support him,” Trombly said, meaning Mashaw.“He was in charge so I was standing back.”
Sgt. Glenn Trombly after testifying against his former colleagues. Photo credit: JB Nicholas.
But the body-camera video captured him, not Mashaw, directing Kieffer to leave the room where Brooks was assaulted. And Trombly also admitted he, not Mashaw, ordered Galliher to retrieve leg irons for Brooks, which Galliher did, video shows.
Trombly also directed the attempted cover-up—not Mashaw.
Trombly not only ordered the guards to re-write false reports that attempted to justify Brooks’ killing, Trombly himself wrote the false report defendant Kingsley submitted. He said he did it because he sent Kingsley to the hospital with Brooks.
Defense lawyers fought hard on cross-examination to elicit crumbs from Trombly that helped their clients.
Luke Nebush, Kingsley’s lawyer, got Trombly to admit that he himself wrote the false report Kingsley signed and submitted.
Longeretta, Kieffer’s attorney, elicted testimony from Trombly that guards are divided into two categories determined by the kind of violence they use against prisoners: whether they are “hands on” or prefer to use pepperspray.
Kieffer preferred to use pepperspray, according to Trombly.
Kevin Luibrand, Galliher’s lawyer, got Trombly to say he ordered his client to get the leg shackles Galliher put on Brooks—although Trombly tried to split hairs by also claiming he didn’t specifically order Galliher to put them on Brooks.
Trombly called what he did “shameful. I regret it. I wish I could change it. I knew what I did was wrong.”
Fitzpatrick, the Special Prosecutor, rested the People’s case when Trombly concluded his testimony shortly before 1:00PM.
All three defendants moved to dismiss, arguing the People hadn’t proved their clients’ guilt beyond a reasonable doubt. Oneida County judge Robert L. Bauer denied the motions and asked the defendants’ lawyers if any of them had any witnesses to call or evidence to present.
Before that moment, defense lawyers appeared to be prepared to call at least two witnesses who briefly appeared in the hallway outside the courtroom, but ultimately they didn’t and they told judge Bauer their clients didn’t want to testify either.
That caused Judge Bauer to tell the defendants they had the right to testify. He asked them if they wished to do so. Kieffer and Kingsley stayed seated and said no.
Galliher rose to his feet and spoke a single, solitary sentence: "Yes I choose not to testify."
At that, Judge Bauer dismissed the jury for the day.
Closing arguments are set for 10:00AM Wednesday followed by the judge's instruction to the jury on applicable law. The jury will probably get the case just before lunch.
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