WASHINGTON, May 26 -- The gunman of a deadly shooting in a Walmart supermarket of North Dakota earlier on Tuesday has been identified as an Air Force airman, police said.

Marcell Willis, 21, walked into a Walmart supermarket, shot two employees, killing one, before ending his own life in the store. He also fired once at a third employee but missed, according to Grand Forks police.

"We've not been able to find any links to him and any of the victims. That's not to say that can't change," police spokesman Derik Zimmel told reporters, "There's no apparent motive that jumps out at this time."

The injured worker was taken to Altru Hospital in Grand Forks with a gunshot wound that was not believed to be life-threatening, Zimmel said. Willis received medical treatment at the scene and taken to Altru, where he was pronounced dead.

Willis was the only person with a handgun and no police officers fired a weapon, Zimmel said.

"We are deeply saddened about this situation and our thoughts and prayers are with the victims and their families," Walmart spokesman Brian Nick said.

The Grand Forks Air Force Base, where Willis was stationed, said that they are working with police on the case. The base has 3, 000 Air Force personnel and civilians, according to its website.

The Walmart is one of the two in Grand Forks, a northeastern city of North Dakota. The city has a population of 55,000 people.