NORMAN, Okla. —  A University of Oklahoma (search) student with "emotional difficulties" was identified Sunday as the person who apparently committed suicide near a packed football stadium using an explosive attached to his body.

The remains were believed to be those of Joel Henry Hinrichs III (search), according to Salvador Hernandez, special agent in charge of the FBI in Oklahoma.

University President David Boren (search) has said the blast was an apparent suicide.

"We know that he has had what I would call emotional difficulties in the past," Boren said. "There is certainly no evidence at this point which points to any other kind of motivation other than his personal problems."

Hinrichs, 21, was killed when the explosive device detonated Saturday evening near Oklahoma Memorial Stadium, where more than 84,000 people were watching a football game between the Oklahoma Sooners and Kansas State.

No spectators were injured. The game continued without interruption, and no announcement was made until the final minutes. Spectators were kept from leaving until about 30 minutes after the blast.

Part of the student apartment complex where Hinrichs lived was evacuated after the explosion. Boren said residents would not be allowed to return until authorities knew the area was safe.

"They're going through everything with a fine-toothed comb," he said.