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 wound and the pistol was found under her body, Aaron said.

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

Asked if the deaths could have been caused by a lover's 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.

McNair and Kazemi had been together just two days earlier, when she was pulled over driving a 2007 Escalade registered to her and McNair. She was arrested on a DUI charges, and he was allowed to leave in a taxi.

The bodies were discovered by McNair's longtime friend, Wayne Neeley, who rents the condo in the upscale Rutledge Hill neighborhood with McNair.

Neeley then called Robert Gaddy, who had been friends with McNair since they played at Alcorn State. Gaddy alerted authorities.

People have certain things that they do in life," Gaddy told The Associated Press on Sunday. "We don't need to look on the situation at this time (but) on the fact we just lost a great member of society.

Cook said he was not aware that McNair was seeing Kazemi, a woman whose name the agent learned about through reports of the shooting.

It doesn't make any sense. I don't know what to say," Cook said.

Police said a witness saw McNair arrive at the condo between 1:30 and 2 a.m. Saturday and that Kazemi's vehicle was already there. The condominium is located within walking distance of an area filled with restaurants and nightspots, a few blocks from the Cumberland River and within view of the Titans' stadium.

Fred McNair, Steve McNair's oldest brother, said some family members would likely travel to Nashville on Monday to consult with Mechelle.

It's still kind of hard to believe," Fred McNair said. "He was the greatest person in the world. He gave back to the community. He loved kids and he wanted to be a role model to kids.

McNair and his wife split their time between Nashville and their farm in Mount Olive, Miss., according to a statement from the Titans.

An arrest affidavit from Thursday said Kazemi had bloodshot eyes and alcohol on her breath when she was pulled over, but refused a breathalyzer test, saying "she was not drunk, she was high.

McNair and his family frequented the restaurant where Kazemi was a waitress, according to employees and patrons of Dave & Buster's in Nashville.

She was reliable 90 percent of the time," manager Chris Truelove said of Kazemi. "She was pretty outgoing. A lot of the guests liked being around her, and she liked being around the guests.

Co-worker Shantez Jobe, 33, said she was friends with Kazemi.

We talked about who had more fashion sense, and who was the cutest, and who could get more boys, you know some of the stuff girls do," Jobe said.

In June, McNair opened a restaurant near the Tennessee State University campus. It was closed Saturday evening, but had become a small memorial, where flowers, candles and notes had been placed outside the door.

McNair led the Titans to the 2000 Super Bowl, which they lost 23-16 to the St. Louis Rams. He was co-MVP of the NFL with Colts quarterback Peyton Manning in 2003.

Manning said in a statement Sunday that he had some great battles with the quarterback.

Sharing the NFL MVP honor with him in 2003 was special because of what a great football player he was," Manning said. "I had the opportunity to play in a couple of Pro Bowls with him, and the time spent with him in Hawaii I'll never forget. I'll truly miss him. My condolences go out to his family.

McNair's most notable moment came in the 2000 Super Bowl. With the Titans trailing by seven, he led the team 87 yards in the final minute and 48 seconds, only to come up a yard short of a touchdown. Kevin Dyson caught his 9-yard pass, but was tackled at the 1-yard line by the Rams' Mike Jones.

McNair accounted for all of Tennessee's yards in that drive, throwing for 48 yards and rushing for 14. The rest of the yardage came on penalties against the Rams. Before that, he brought the Titans back from a 16-0 deficit to tie the game.

If you were going to draw a football player, the physical part, the mental part, everything about being a professional, he is your guy," former Ravens and Titans teammate Samari Rolle said. "I can't even wrap my arms around it.

McNair grew up in rural Mount Olive, Miss., and became a nationally known college football star playing for Alcorn State, a Division I-AA school in his home state. He was so dominant in the Southwestern Athletic Conference, he became a Heisman Trophy contender. National media flocked to little Lorman in the southwest corner of the Magnolia state to get a look at "Air McNair." He still holds the Division I-AA (now known as Football Championship Subdivision) records for career yards passing (14,496) and total offense (16,823).

McNair was the third overall draft pick in 1995 by the Houston Oilers, who eventually became the Titans. He finished his career with 31,304 yards passing and 174 touchdowns. McNair's rugged style led to numerous injuries and aches. He played with pain for several years, and the injuries ultimately forced him to retire.

During a five-game stretch at the end of the 2002 season, McNair was so bruised he couldn't practice. But he started all five games and won them, leading the Titans to an 11-5 record and a berth in the AFC championship game for the second time in four seasons.

McNair played all 16 games in 2006, his first season in Baltimore, and guided the Ravens to a 13-3 record. But he injured his groin during the season opener in 2007 and never regained the form that put him in those Pro Bowls.

McNair is survived by Mechelle, his wife of nearly 12 years; and sons Junior, Steven, Tyler and Trenton.