Of the nine Roxbury Correctional Institution officers charged with second-degree assault in connection with a March 2008 assault on an inmate, the fate of only one remains unknown.
A trial for Scott Boozel, 28, ended June 16 with a hung jury, and a judge declared a mistrial.
Prosecutors have not decided whether to retry Boozel, according to Raquel Guillory, director of communications for the Office of the Attorney General.
Prosecutors in June dropped a second-degree assault charge against Reginald Martin, 38.
Two of the officers, Timothy Mellott, 23, and Lucas Kelly, 29, who now lives in Wyoming, agreed to testify against their former colleagues as part of a plea agreement. Court records show that sentencing dates for Mellott and Kelly have not been set.
Robert Harvey, 63, and Keith Morris, 27, were acquitted in September.
Tyson Hinkle, 34, Michael Morgan, 39, and Dustin Norris, 25, were acquitted Wednesday.
-- Erin Julius