This was part of an ongoing hearing to determine if three jail guards will be tried for murder.
WATCH VIDEO: EXCLUSIVE: Attorney describes inmate's alleged beating by Santa Clara County deputies
The former inmate testified that he saw Michael Tyree on the floor of his cell following the beating and when one of the officers went to check on him he used his boot to nudge his head. This, as the inmate alleges the guards targeted and bullied mentally ill inmates.
The attorney for Michael Tyree's family recounts what witness Juan Perez testified in court.
"What he conveyed in his testimony was so intense. Meaning how mean Officer Lubrin treated the mentally ill inmates. It was just so mean that that itself was crazy," said Michale Tyree's attorney Paula Canny.
Perez says he witnessed the accused Santa Clara County jail guards. Rafael Rodriguez, Matthew Farris, and Jereh Lubrin enter inmate Tyree's cell the night of his death.
"To Michael Tyree's cell the boom, boom and Michael's cries for help and then just silence," Canny said.
RELATED: 3 Santa Clara County deputies may go on trial for inmate death
Now, the correctional deputies face murder charges for Tyree's death and assault under the color of authority charges for the alleged beating of another inmate, Juan Villa, who's also mentally ill.
"He touched people's lives. He mattered," said Shannon Tyree, Michael Tyree's sister.
Shannon Tyree broke down in court as the inmate witness said Lubrin checked on Tyree who was on his cell floor following the beating, by nudging his head with his boot.
"We looked at his corpse yesterday. I looked at my brother and I thought that is a corpse. He is gone, but he was naked. He was covered in feces and vomit and that's public now. You know, those are the last images of my brother and the last thing this man did for him was kick his head," Shannon Tyree said.
She wants to share these photos of Michael Tyree as more upsetting details are expected to be released during the hearing.
Juan Villa is expected to testify Wednesday.