By Ruthy Munoz

WASHINGTON (Reuters) - The 25-year-old former U.S. Army reservist who shot dead five Dallas policemen in a racially motivated sniper attack was a poor marksman during basic training, a soldier who served with him said.

Dallas police have said that the gunman, Micah Johnson, used "shoot and move" tactics to ambush the officers as a July 7 demonstration over police involved shootings of African-Americans was wrapping up, leading police to believe at first that there was more than one sniper.

"If I remember right, Micah had a really hard time at the range," William Krenn, 28, who served in the Army National Guard until 2014, said in a telephone interview on Wednesday. "He did not do well with his weapon. He struggled to pass basic marksmanship."

Krenn, who lives in St. Francis, Wisconsin, provided Reuters with copies of documents showing his military service.

"If I remember right, he was one of the guys who had to continue to go back up to the line to try to qualify with his M16 because he couldn't qualify with it, so I kind of found that interesting after learning that he did that," Krenn said.

Dallas police said Johnson told them that he was angry about police killings of two black men in Louisiana and Minnesota earlier that week and wanted to "kill white people," especially police. Johnson was killed when police detonated a 'robot bomb' in the parking garage where he hid.

Krenn, who is white, remembered Johnson as an affable if slightly disheveled soldier who got along with his peers of all races during nine weeks of basic training at the Fort Sill, Oklahoma, base in 2009.

Johnson was in the U.S. Army Reserve from 2009 to 2015 and served in Afghanistan. Krenn said that during basic training Johnson occasionally joked about white people, but did so in a light-hearted way and did not appear to harbor racial animosity.

Krenn said Johnson was a careless, even "sloppy" soldier who possibly did not take his training as seriously as others, but he showed no signs of the violence in his future.

Krenn recalled hearing that Johnson was the Dallas gunman.

"I was just so shocked. I was driving my car and I had to pull over because I was full of goosebumps and I was shaking," Krenn said. "I just could not believe that this goofball, light-hearted kid that I went to training with did something so evil."

(Reporting by Ruthy Munoz; Writing by Dan Whitcomb; editing by Daniel Wallis and Grant McCool)