The first named victim among five Dallas law enforcement officers shot dead on Thursday was a recently remarried transit police officer who had helped train police in Iraq, officials and local media said.

Nine other people including seven officers were also wounded in the shooting at the end of a protest over this week's killing of two black men by police in Baton Rouge, Louisiana and a suburb of St. Paul, Minnesota.

Transit Police Officer Brent Thompson, 43, had worked for the Dallas Area Rapid Transit (DART) system since 2009 and was the first officer killed in the line of duty since the transit system formed a police department in 1989, DART said on its website. He previously worked for a private U.S. military contractor as a trainer in Iraq.

"As you can imagine, our hearts are broken," a DART statement said.

Thompson was married to a fellow DART officer, local television station WFAA reported, citing DART Chief James Spiller. USA Today reported that they married about two weeks ago and that Thompson was also a father and a grandfather from a previous marriage.

On his LinkedIn profile, Thompson said, "I am constantly looking for different ways to serve the department; this helps to keep my work from becoming sedentary and boring."

He attended the police academy at Navarro College in the Dallas/Fort Worth area and later taught classes there, according to his LinkedIn profile.

He spent more than four years in Iraq, working for U.S. contractor DynCorp International as a police liaison officer who supervised Americans training and mentoring the Iraqi police force, the LinkedIn profile says.

Thompson's Facebook page reflected the life of a devoted father, with numerous photos of family posted to his account.

"My family," Thompson wrote in a caption accompanying a photo on his Facebook page. "I'm so blessed."

Thompson posted numerous pro-police memes on his Facebook timeline, some of which mocked the "Black Lives Matter" movement and accused U.S. President Barack Obama of not adequately supporting law enforcement.

On a post that read "police lives matter" Thompson wrote, "Although our president, attorney general, and the great Reverend Al Sharpton don't agree, law enforcement officers' lives count too."