DUBLIN, Calif. (AP) — A California county sheriff’s office arrested four of its own deputies who are accused of allowing a maximum-security prisoner to throw feces and urine at other inmates.

The East Bay Times reports the Alameda County Sheriff’s Office arrested its deputies on Thursday on charges of mistreating inmates at Santa Rail Jail.

One deputy resigned and three others have been placed on administrative leave after Sheriff Gregory Ahern launched an investigation in January. The three on leave are 26-year-old Sarah Krause, 23-year-old Justin Linn and 27-year-old Erik McDermott, while Stephen Sarcos resigned.

Inmate Ruben Febo Jr. says he is housed in the same area where the mistreatment took place. He recently wrote a letter to the East Bay Times saying he was placed in cell that was “saturated in feces.”