NASHVILLE, Tenn. — Former NFL quarterback Steve McNair's shooting death was a homicide, police said Sunday, but authorities stopped short of saying it was a murder-suicide committed by the 20-year-old girlfriend found dead by his side.

McNair, 36, was shot four times, twice in the head, by a semiautomatic pistol, Nashville police spokesman Don Aaron said. The woman, Sahel Kazemi, was killed by a single gunshot and the pistol was found under her body, Aaron said.

Aaron said the two had been in a "dating relationship for past several months."

Asked if the deaths could have been caused by a lovers' quarrel, Aaron said, "That's a very important part of the investigation as we work to ultimately classify Miss Kazemi's death."

Police said they need to do more interviews with friends of Kazemi and McNair before they rule on whether her death was a suicide, Aaron said.

McNair, a four-time Pro Bowl selection, was married with four children. He and Kazemi were found dead Saturday afternoon at a Nashville condominium he shared with a friend, and police said Sunday that it appears the two died in the early morning.

Police earlier said they weren't looking for any suspects and do not believe McNair's wife was involved. Mechelle McNair, mother of two of his four sons, was expected to collect her husband's belongings from authorities. Funeral arrangements were not expected to be finalized until Monday afternoon at the earliest.

"She's still very upset, very distraught," agent Bus Cook said.

McNair led the famous Tennessee Titans' drive that came a yard short of forcing overtime in the 2000 Super Bowl, before the Titans traded him to the Baltimore Ravens in 2006. "On the field, there isn't a player that was as tough as him," the Ravens' Derrick Mason said.

McNair retired last year and had recently opened a restaurant in Nashville, where he shared a condo with a friend.

A man who answered the door at a house in the Jacksonville, Fla., suburb of Orange Park said it was the home of Kazemi's family but said her relatives did not want to comment.

"We don't have anything to say, please leave us alone," he said.

A Nashville neighbor saw McNair, 36, at Kazemi's Nashville apartment so often — two to three times a week — that she thought McNair had moved in. McNair never tried to hide his presence but kept to himself.

Neighbor Reagan Howard said Kazemi often was dropped off in the early morning hours by a limousine and upgraded recently from her Kia to a Cadillac Escalade.

"It was pretty obvious that she was taken with him," Howard said.