NEW YORK (CBS) What Robert Gaddy saw in NFL star Steve McNair's rented Nashville condo will haunt him for the rest of his life.
In a desperate 911 call, he cried, "Oh my god...somebody's been shot. I haven't checked the vitals."
"Is the person breathing," the operator asks.
"It don't look like it," he says.
Listen to the Chilling 911 Call.
Slide Show: McNair's Mistress and Hidden Life.
Gaddy, confronted with the site of McNair murdered on the couch and McNair's mistress, Sahel Kazemi, lying dead in a pool of dark blood on the floor, was so stunned he can be heard gasping for air on the call.
Gaddy had arrived at the grisly murder scene after getting a call from Wayne Neeley, a friend who shared the condo with McNair. Neeley was the first person to discover the dead couple, but was so shocked he didn't call 911 himself, police say.
According to police, McNair was shot twice in the chest and once in each temple, the final shot at very close range. Kazemi died of a single gunshot to the head.
On the 911 call, Gaddy can be heard leaving the apartment to ask passersby for the apartment's street address. He then says, "I hate to be the one that makes this call. It's so messed up."
Police are now convinced that Kazemi murdered McNair in his sleep. They say she was motivated by a fear McNair had another young lover and mounting financial problems.
McNair's wife was unaware of the affair before the murder, according to family members.
Kazemi's family was equally shocked by the turn of events. They say Kazemi seemed happy and was confident McNair would leave his wife for her.
Gaddy, a longtime friend of McNair, was relieved when police said his friend did not suffer.
PREVIOUSLY ON CRIMESIDER
July 9, 2009 - Caught on Tape: McNair's Mistress DUI Video
July 8, 2009 - McNair Murder: The Mistress Did It
July 8, 2009 - Love Pad to Death Pad: Gruesome Details of NFL Star's Murder Scene
July 7, 2009 - McNair Murder: The Girlfriend's Gun
July 6, 2009 - The Girl, The Gun and The Dead NFL Star