Brent Thompson, a Dallas Area Rapid Transit officer killed during unrest overnight in Dallas, was the first officer killed in that agency’s line of duty.

“Brent was a great officer,” said James Spiller, police chief of DART. “He was an outstanding patrol officer as well as a rail officer. We have the highest respect for him.”

Spiller and Gary Thomas, DART’s president/executive director, talked about Thompson and the violence in Dallas in appearances Friday on CNN’s “New Day.”

Twelve officers were shot — five are dead and seven injured — in the attack in downtown Dallas, the Dallas mayor’s office said Friday. The violence came amid protests over the deaths of two African-American men by police officers in Minnesota and Louisiana.

Four of the other slain officers were with the Dallas police.

A police trainer in Iraq, Afghanistan

Thompson, 43, a nearly seven-year veteran of the transit force, got married in the last two weeks, Spiller said. His spouse was a fellow transit officer

“He was in great spirits from his recent marriage,” Spiller said.

According to Thompson’s LinkedIn.com profile, he was “motivated by a ” ‘Team’ atmosphere.”

“I enjoy working on challenging tasks and problem solving with my peers. I am constantly looking for different ways to serve the department, this helps to keep my work from becoming sedentary and boring,” the officer said in his LinkedIn summary.

Thompson was an international police liaison officer for DynCorp International for nearly five years, starting in 2004, his profile said.

“My last position as an IPLO was Chief of Operations for Southern Iraq. I was responsible for the day to day operations conducted by our American police officers who trained and mentored the Iraqi Police,” he said on his profile.

He was in southern Afghanistan as well, according to the profile, where he was a “Team Leader” and “Lead Mentor” to the “Southern Provincial Police Chief.”

“In all locations we mentored and taught our Iraqi/Afghan counterparts democratic policing, and assisted in the establishment of the police department in these locations.”

During the “New Day” interview, Thomas touched on Thompson’s international service.

“He was a dedicated officer, dedicated to the safety of Americans, all over the world certainly,” he said.

According to his LinkedIn profile, Thompson lived in Carrollton, Texas. Spiller said Thompson hailed from Corsicana, Texas, south of Dallas.

According to his LinkedIn profile, Thompson attended high school there and taught at Navarro College Police Academy, also in Corsicana.

Patrick Zamarripa: Navy veteran and father of two

Patrick Zamarripa, a father of two, was one of the four Dallas police officers who died, according to social media posts from family members and reports from local news outlets.

Military records show he was a U.S. Navy veteran who had been deployed to Bahrain as part of the Iraq War effort.

His brother shared a photo on Twitter with the caption: “Love you brother. Couldn’t be prouder. We’ll see you again. #PrayForDallas.”

In Facebook post, Patrick’s father, Rick Zamarripa, said his son had been taken to Parkland Hospital and asked for prayers.

The names of the other three Dallas police officers have not been released.