A jury trial began Thursday for a Denver police officer who struck a handcuffed 17-year-old boy three times after an arrest last year.

Prosecutors say the officer, Dat Truong, 32, hit the boy out of anger and frustration after the teenager’s disrespectful “smack talking.” The officer’s defense attorney said the strikes were a legitimate use of police force aimed at curtailing the handcuffed boy’s threatening behavior.

Truong is charged with a single misdemeanor count of harassment over the strikes. He will be disqualified from working as a police officer in Colorado if he is convicted of the crime.

The incident happened on the night of Nov. 3, 2023, after Denver police tried to stop a vehicle driven by the 17-year-old boy. The teenager did not stop, and then crashed his vehicle near the intersection of East Colfax Avenue and Interstate 225 in Aurora.

The vehicle rolled over and the airbags deployed. All five people in the car ran from police, including the 17-year-old. He was later found hiding in a nearby mobile home park and was arrested by Denver and Aurora police officers.

After the teen was arrested, searched twice and handcuffed with his hands behind his back, Truong put him in the front seat of his patrol car and buckled the seatbelt.

Throughout the arrest, the teenager loosed a litany of disrespectful comments, prosecutor Tod Duncan told jurors during opening statements Thursday.

“It’s pretty shameful language,” he said. “You wouldn’t want your mother to hear it.”

Truong responded with his own profanity, eventually telling the boy to “Shut his dumb (expletive) up,” according to body-worn camera footage of the arrest. Then, after the teenager was handcuffed and buckled into the front passenger seat of the patrol car, Truong reached over and struck him three times, the footage shows.

The teenager testified Thursday that the officer punched him with a closed fist three times on his upper left arm and that Truong’s actions made him feel unsafe and hurt.

“He was an adult, he was a police officer; it is a position of power, a position of trust,” Duncan told jurors. “He is sworn to serve, he is sworn to protect. And he reached out in frustration and anger and he struck (the teenager) three times as he sat with his hands cuffed behind his back.”

Truong’s defense attorney, Ryan Brackley, said the officer was responding to a particular comment the teenager made about pulling the car over so he could fight the officer, and how the officer wouldn’t be as tough without his badge.

“Fighting words,” Brackley said. The boy “turned his body” toward the officer, he told jurors.

“Under the circumstances — police officers, we talk about reasonable force — he shoved him away,” Brackley said. “… That is the only force that was used in this case. And it was reasonable force under the circumstances, under the uncertainty, under the tension, under the rapidly changing circumstances in that car.”

The teenager later told officers that the officer’s punches didn’t hurt. On the stand Thursday, he said he lied about that because he both wanted to seem tough and wanted to get away from officers as quickly as possible after the incident.

The trial in Adams County District Court is expected to conclude Friday.

Truong, a Denver police officer since 2014, was placed on desk duty after the incident and remains on the force, according to state records.