Nashville police now think the gun recovered at the scene of Steve McNair and Sahel Kazemi's shooting death belonged to Sahel.
Police spokesmen Don Aaron said, "We believe the pistol recovered from the apartment was purchased by Kazemi."
McNair was found shot four times -- twice in the head and twice in the body -- and Kazemi suffered a single gunshot to the head. Cops were told Kazemi and McNair "had been in a dating relationship," even though McNair was married.
The gun in question was found under Kazemi's body -- cops think murder-suicide is a possibility, but nothing official yet.