The trial of an NYPD sergeant accused of killing a Bronx man with a cooler began Tuesday at Bronx Supreme Court.

Prosecutors say Erik Duran, a sergeant with the New York City Police Department, caused the death of 30-year-old Eric Duprey during a police pursuit three years ago — an incident that was captured on surveillance video.

News 12 was inside the courtroom as the trial began.

There was no jury in the trial.

"He chose a bench trial because he knows that a jury from the Bronx would send him straight to jail," said Hawk Newsome, founder of Black Lives Matter Greater New York.

Duran sat with his attorneys. He remained focused and showed no emotion as both legal teams gave their opening statements.

The prosecution called Duran "negligent" and said that the incident was "not an accident."

New details were revealed in the case. Duran, a former Bronx narcotics detective, was involved in an undercover operation. His team was intending to arrest Duprey on drug charges.

"Many mistake were made," said the prosecutor. They revealed the officers arrested the wrong man, prompting Duprey to flee on a moped.

The 2023 video shows Duprey riding away on a scooter when a 40-pound cooler was thrown in his path, knocking him to the ground. Police say Duprey was attempting to flee during a drug bust when Duran allegedly threw the cooler in an effort to stop him. Duprey was pronounced dead at the scene.

"The law doesn't allow police to use deadly force to make an arrest," said the prosecutor.

The defense team spoke about Duran's long history in the Bronx, from childhood to serving the community.

They claimed Duprey was illegally driving an unregistered moped on the sidewalk before he was struck. They said the moped would have hit two officers and the person they detained if Duran did not intervene.

Opening statement revealed Duran had approximately 2.5 minutes to make a life-or-death decision. The defense said "the use of the cooler is irrelevant."

Duprey's mother, Gretchen Soto, appeared as the first witness. She was seen holding back tears recounting the last time she saw her son.

Officer Brandon Pehler appeared as the second witness. He detailed his experience responding as backup after Duprey was struck.

Advocates for the family argue Duran's actions were excessive and unnecessary. The city medical examiner later ruled Duprey's death a homicide.

Protesters rallied outside of the courthouse, calling for accountability.

"This isn't about a trial. This is about the truth. This is about an officer who had 17 allegations of misconduct. This is about an officer who should not have been on the streets," said Chivona Newsome, co-founder of Black Lives Matter Greater New York. "Having a badge is not a license to kill."

Duprey's family members and Black Lives Matter activists are expected to be present in court throughout the trial, saying they will continue to show up in support until justice is served.

Duran has pleaded not guilty to multiple charges, including manslaughter, assault and criminally negligent homicide. If convicted of the top charge, he could face up to 25 years in prison.