Three California correctional deputies have been arrested after an inmate under their watch was found dead of multiple blunt trauma injuries, authorities said on Thursday.

Santa Clara County sheriff’s spokesman Sgt. James Jensen said the jail guards – Rafael Rodriguez, 27, Jereh Lubrin, 28, and Matthew Farris, 27 – remain in custody without bail.

Medical Examiner Dr. Joseph O’Hara said that Michael James Pipkin Tyree, 31, died of multiple blunt force injuries, “visceral lacerations” and internal bleeding.

An emotional Santa Clara County Sheriff Laurie Smith apologized on Thursday to Tyree’s family and said “the disappointment and disgust I feel cannot be overstated.” She was flanked by 18 uniformed officers, and at least another dozen members of her agency in plain clothes attended a news conference.

The details surrounding Tyree’s death remain murky. Last Thursday, Tyree and other inmates in his jail wing were securely locked in their cells when the beating apparently took place. Smith refused to provide details, but said the three officers were conducting a routine clothing search and left the wing.

She said about an hour later one officer re-entered the cell and issued a “man down” call. Tyree was seen naked and covered in feces and vomit. He was declared dead by responding paramedics.

Smith said she has apologized directly to two of Tyree’s three sisters, and repeated her “profound sorrow” over his death.

The guards involved in Tyree’s death were removed from duty, stripped of their weapons, uniforms and peace officer status the next day, Smith said. It took several more days for them to be arrested. They are currently on unpaid administrative leave, Smith said.

Attorney Paula Canny, representing Tyree's family, commended the sheriff for an "extraordinary" response.

"This could have been dragged out," Canny said.

Canny urged community members to think about “how we, as a system, treat mentally ill people” and said she hopes the district attorney will bring the officers to justice.

Raj Jayadev, director of local civil rights organization Silicon Valley De-Bug which works to support families of people in the criminal justice system, said he hopes there are investigations into other abuse complaints at the county jail.

His organization has heard frequent claims, he said, but filing complaints is challenging because it can put inmates at additional risk.

He said he's hopeful Smith was sincere in her commitment to fully investigate.

Attempts to reach relatives of the deputies were unsuccessful Thursday.

Tyree was homeless and waiting to be transferred to a mental-health facility when he died. He was serving a 5-day sentence on a petty theft charge.

A former girlfriend told the San Jose Mercury News that Tyree had hoped for a life of peace and tried unsuccessfully to keep his bipolar disorder in check.

Lindsay Solomon, who dated Tyree when she was a teenager in Coral Springs, Florida, told the paper he could get "very agitated and agitate someone else. I could see it escalating."

"But if you're a police officer, or a guard, you should have better judgment than that," she told the newspaper.

The Associated Press contributed to this report.