By Greta Stuckey
syracuse.com
UTICA, N.Y. — A former Marcy corrections officer will receive a shorter prison sentence after accepting a plea deal Thursday in exchange for testifying against his co-workers last fall.
Robert Kessler pleaded guilty to second-degree assault in October. Under an agreement reached Thursday, he will serve four years in prison, reduced from a sentence of five to seven years, in exchange for his cooperation, according to Onondaga County District Attorney William Fitzpatrick.
| READ NEXT: The duty to intervene: A reflection on the Robert Brooks incident
Nine corrections officers and a prison sergeant faced charges related to the fatal beating of Robert Brooks.
On Dec. 9, 2024, several corrections officers repeatedly punched and kicked Brooks in the groin, abdomen and face in the infirmary at the Marcy Correctional Facility. He died hours later at a Utica hospital. Some of the beating was captured on the prison guards’ body cameras.
In October, Kessler testified against three of his co-workers who were facing murder charges in the fatal beating.
As part of the plea deal, Kessler described in detail how guards pepper sprayed, beat and punched Brooks in prison until he wasn’t moving.
Kessler also testified about the attempted cover-up, describing how he was ordered to keep rewriting his report on what happened. He said the earlier versions were shredded.
The other guards
Here is what has happened to the 10 corrections officers charged in connection with Brooks’ death.
- Nicholas Anzalone pleaded guilty to first-degree manslaughter. He was sentenced to 22 years in prison.
- Anthony Farina pleaded guilty to first-degree manslaughter. He was sentenced to 22 years in prison.
- Christopher Walrath pleaded guilty to first-degree manslaughter. He was sentenced to 15 years in prison.
- Sgt. Michael Mashaw pleaded guilty to second-degree manslaughter. He was sentenced to 3 to 9 years.
- Michael D. Fisher pleaded guilty to second-degree reckless endangerment after a jury entered a deadlock after five days of trial. He was sentenced to six months in jail, though the sentence will be deferred while Fisher appeals the prosecution’s theory of his criminal liability.
- David Walters pleaded guilty to second-degree manslaughter. He was sentenced to 2 1/3 to 7 years.
- Glenn Trombly pleaded guilty to second-degree gang assault. He was sentenced to four years.
Three other former officers went to trial in October. All three men were charged with second-degree murder and first-degree manslaughter.
- David Kingsley was found guilty of both charges. He was sentenced to 25 years to life in prison.
- Mathew Galliher was acquitted of all charges.
- Nicholas Kieffer was acquitted of all charges.
Staff writer Anne Hayes contributed to this report.
—
©2026 Advance Local Media LLC. Visit syracuse.com. Distributed by Tribune Content Agency, LLC.