Defense attorneys countered that the footage depicted a violent and uncooperative Thomas who gave officers the fight of their lives.
The recording begins with Ramos, responding to a report of someone rattling car doors, approaching a disheveled, shirtless Thomas outside a downtown Fullerton bus depot.
Ramos orders Thomas to sit on the curb with his feet out and hands on his knees. A frustrated, and at times sarcastic, Thomas appears to have a difficult time following his commands.
About 15 minutes into the video, Ramos puts on latex gloves and puts his fists in front of Thomas' face. "Now you see my fists?... They're getting ready to f— you up."
"Start punching, dude," Thomas said.
Moments later, a relatively calm situation quickly escalates. Ramos grabs his arm; Thomas pushes it and starts to move away from Ramos, who takes out his baton. As Thomas is walking away, another officer is seen swinging his baton at the homeless man's legs.
(That officer, Joe Wolfe, was charged with involuntary manslaughter, but Rackauckas said Monday prosecutors would not pursue that case after Monday's verdict.)
Soon Thomas is on the ground fighting with six officers.
"I can't breathe," Thomas said. "Dad, help me! Dad, help me!"
Cicinelli struck Thomas on the face with his Taser at least twice. Defense attorneys said he did it as a last resort when the device failed to work properly and only after Thomas attempted to take it away from him.
They said the video showed officers who were following their training, not out of control.
Without the video, "we would've heard some screaming and crying, but never have seen what happened," said Michael Schwartz, Cicinelli's attorney. "Which was a very measured reaction with police officers trying to control a suspect."
As the verdicts were coming down, Schwartz quietly and repeatedly said "Thank God." Seconds later, when Cicinelli was found not guilty of involuntary manslaughter and excessive force under the color of authority, he tightly embraced him.
"The video, in my eyes, is what helped the most," Schwartz said.
Accounts from witnesses and family photos of Thomas' pummeled face created an immediate public furor at the time of the incident.
People crammed Fullerton meetings to reprimand or shout at city leaders. Eventually, officials' response to the incident led to the ouster of three City Council members and the retirement of Fullerton's chief of police.
The coroner who conducted Thomas' autopsy said he died of brain damage from lack of oxygen caused by chest compressions and injuries he sustained at the hands of police.
But even that finding was highly contested, and the question of what exactly killed Thomas — a weak heart, chest compressions or an intubation tube — took up a large portion of the case.
Defense attorneys attempted to cast doubt as to the cause of death, challenging the testimony of the coroner and presenting evidence and witnesses that offered alternative causes of death.
They brought in Dr. Steven Karch, a forensic pathologist who studies how drugs affect the heart. After viewing slides of Thomas' heart cells, Karch said his death was caused by an enlarged heart due to previous methamphetamine use.