EDGARD, La. -- Denis Amaya-Rodriguez is on trial for negligent homicide, reckless operation and driving without a license, among other charges.

The Honduran national was driving a party bus to Baton Rouge when the bus crashed killing three people and injuring dozens others in August 2016. St. John District Fire Chief Spencer Chauvin was killed in that crash.

When dash cam video was going to be shown of the scene, some of Chauvin’s family members walked out of the courtroom in tears.

According to Louisiana State Police, authorities were responding to an early morning crash on Interstate 10 in Laplace.

St. John firefighters went to the scene and parked a firetruck on an angle to protect first responders and let drivers know they need to switch lanes. Flares were also put out.

A party bus driven by Rodriguez hit the fire truck, rear ended a car and killed two people inside before crashing into the firemen.

State troopers said Amaya’s drug test was clean and he was not on a cell phone when the crash happened.

His attorney hinted that the brakes didn't work, but a trooper who specializes in reconstructing crash scenes says based on tire marks left on the roadway the brakes were locked up but still should've worked.