The three Santa Clara County correctional officers charged in the beating death of a mentally ill inmate pleaded not guilty in court on Tuesday.

Jereh Lubrin, Matthew Farris and Rafael Rodriguez are charged in the murder of 31-year-old Michael Tyree, who was found beaten to death in his cell at the Santa Clara County Main Jail on Aug. 27.

The three correctional deputies sat calmly, and for the most part separately, in court and then each entered his plea of not guilty.

A preliminary hearing is scheduled to start Feb. 29.

Justin Goodwin, an attorney for Tyree's family, said he is glad to see the court process moving ahead.

"What you can never lose sight of as the wheels of justice turn is that, at the heart of this, is someone lost a life," Goodwin said. "A son, brother and friend is dead because of the actions of these defendants."

Each of the three defendants is out on $1.5 million bail.

Last week, the Santa Clara County Sheriff announced some major changes to its jail operation as part of an ongoing evaluation that began following Tyree's death.