TEMPE, Ariz. -- Just after 8:30am Thursday, Steele Campbell started his workday at his office park in Tempe.
"I'm working on the computer and I heard a pop. A coworker said, 'That sounded like a car backfiring!' I'm kind of a gearhead and I know cars don't backfire now," Campbell said.
He looked out and saw Joe Palmisano, a criminal defense attorney who worked next door.
'He's standing here, and he's talking down this way and we can't see anyone there, so we're like, that's kind of weird.'
Police say what Campbell couldn't see, on the ground, where a blood stain remains, was Ryan Hall, 35.
"His ex-girlfriend works with Mr. Palmisano and this all stemmed from that," Said Sgt. Mike Pooley with Tempe Police.
Officers say Palmisano, 48, is now in a relationship with that woman. Could that be why the pair argued? Either way detectives say Palmisano pulled out a gun, and shot Hall, injuring him. Campbell wasn't sure what was happening until he saw that gun.
"He stepped back even further, about here, and you could see the barrel, and I'm like, 'Call 911, we've got a problem,'"said Campbell.
Campbell says the victim, Hall, made his own 911 call and was alert as emergency crews took him away from the scene. He also says Palmisano peacefully turned himself over to police. He's accused of aggravated assault and attempted murder, but Campbell says the attorney's definitely guilty of one thing. Their workplace no longer seems as safe.
"We'll have the door locked from now on," Campbell said.
Hall is in serious condition but is expected to survive.