AKRON, Ohio — An Ohio Marine who was killed in Iraq spent so much time preparing for the military that when he got to boot camp, he could break down a rifle faster than his superiors, his mother said Thursday.

“The drill sergeant didn’t like that,” said Pam Murray, mother of Marine Sgt. Jeremy Murray, who died this week, the family said.

Murray, 28, was killed when a roadside bomb hit his Humvee, family members said. The Department of Defense had no additional information on Murray’s death.

Murray joined the Army after graduating in 1996 from Waterloo High School in Atwater Township, about 20 miles east of Akron. He later became a Marine. He leaves behind a wife and 5-year-old son.

Pam Murray said her only son was an avid hunter and talked constantly about wanting to join the military when he was growing up. She was so familiar with the way her...