Hats off.

A shot at the NFL awaited Brandon O’Brien, but after the bombing attacks at the Boston Marathon, the former Marine knew a greater task was at hand.

Mr. O’Brien was a record-setting standout at Montana State Northern University after serving four years in the military, but as 30-year-old wide receiver from a small school, he was a long shot to make the NFL.

However, the 6-foot-1-inch, 220-pound Mr. O’Brien ran a 4.56-second 40-yard dash and 4.08 in the short shuttle during recent workouts — times that might convince a team to give him a chance.

But after Monday, when two bombs detonated near the finish line of the Boston Marathon, killing at least three and injuring scores of others, Mr. O’Brien decided it was time to again serve his country.