SANTA ANA (CBS) — The chief of surgical trauma at UC Irvine Medical Center took the stand Tuesday as the preliminary hearing in the Kelly Thomas death case continued for its second day.

Prosecutors say Fullerton police officers Manuel Ramos and Jay Cicinelli confronted 37-year-old Thomas on the evening of July 5th about some car break-ins and after a few contentious exchanges, beat him mercilessly into un-consciousness.

Dr. Michael Lewaka testified Thomas quit breathing in an ambulance, and the cause of death was found to be a crushed windpipe.

The defense argued that it was medical error at UC Irvine that led to the death of Kelly after personnel failed to insert a breathing tube.

Lewaka testified that Kelly’s death could have been tied directly to the beating.

Video of the confrontation between Thomas, a schizophrenic homeless man, and Fullerton police officers was shown in public for the first time Monday, shocking many in the courtroom.

People gasped, screamed and some even cried as they watched a video of the July 5 beating, which was captured on a security camera at a Fullerton bus station.

“Dad – they’re killing me!” Thomas, who died days after the altercation, cries out in the video.

Officer Manuel Ramos, who was responding to a call of a car break-in, finds 37-year-old Thomas walking near the scene of the crime. He begins questioning Thomas and calls for back-up assistance.

“Put your hands on your (expletive) knees. Put your feet out in front of you,” Ramos tells Thomas.

“Well, which one is it, dude?” Thomas asks.

“Both,” Ramos responds.

“I can’t do both,” Thomas retorts.

“Well, you’re gonna have to learn real quick,” Ramos tells him.

Ramos and Officer Joseph Wolfe then ask Thomas why he has someone else’s mail in his backpack.

After a few orders, Ramos tells Thomas he’s going to use his fists on him. The two exchange expletives, Thomas gets up, and the batons come out.

“Get on the ground,” an officer yells.

The courtroom audience gasped at what they saw next; officers swinging batons at Thomas and piling on top of him.

Thomas can be heard apologizing to officers, “OK, I’m sorry.”

After repeatedly ordering Thomas to put his hands behind his back, another officer knees Thomas.

“OK man, I can’t breathe,” Thomas says.

Minutes later, another officer, Cpl. Jay Cicinelli, orders Thomas to stop resisting and uses his Taser on him.

As the officers continue to struggle with him, Thomas begs them to stop and cries out for his father.

Thomas’ father, Ron, who had already seen the video, sat calmly through the showing.

As four officers subdue Thomas, one strikes him repeatedly.

After the struggle, Cicinelli can be heard telling another officer he thinks Thomas is on something.

“We ran out of options, so I got the end of my Taser and I probably, I just started smashing his face to hell,” Cicinelli says.

KCAL9 News spoke with Steve Meister, a criminal defense attorney and former L.A. County prosecutor, and Timothy Williams Jr., a police procedures expert and former LAPD detective, about the video and how it will impact the case.

“Look how many officers it took for him to stay still – five,” Meister said. “An unmedicated schizo who was obviously capable to fight five officers who are trained to take down. That presents a danger.”

“Even though charges are about how this ended, the case is about how it started,” he added.

Meister says that if there is a trial, the video will be presented in two different ways: first, showing officers in a dangerous situation, and, on the flipside, officers over-reacting.

“In my opinion, all of this was excessive force,” Williams said. “I’ve been in altercations and I know it doesn’t take all that to control someone who was unarmed.”

Ramos is facing one felony count of second degree murder and one felony count of involuntary manslaughter. Cicinelli faces charges of involuntary manslaughter and use of excessive force.

A judge could rule as soon as Tuesday afternoon whether the case will go to trial.