Oscar Bejar tried to catch Phoenix office shooter, Arthur Harmon

PHOENIX - If you were standing next to an armed killer, would you know it?

Oscar Bejar stepped into an elevator with 70-year-old Arthur Harmon, the man police say would shoot three people, killing two of them, just seconds later.

"We were about to get off and his finger was still on number one shaking, then when I get off the elevator, I just see him press No. 1,” Bejar said. “I just thought he probably forgot something. I get off and walk out. Then 30 seconds walking down the hall I hear people screaming, gun shots, glass breaking."

Bejar told ABC15 he looked out and saw Steve Singer and Mark Hummels lying on the ground in pain, Wednesday at an office building near 16th Street and Glendale Avenue.

"I peep out and I see the old guy, the same old guy that was in the elevator with us," Bejar said. "I see him walking back to the guy who was screaming. I thought he was going to help him out, but he pulled out a revolver."

Bejar said he witnessed Harmon shooting Singer and Hummels.

Bejar said he knew he couldn't let Harmon get away, so when he spotted him driving out of the parking lot, he jumped into his own car and tailed him.

"I just follow him. He sees me following him, I think. He pulls over at the first street heading east, and then he pulls out a rifle, points it at me, and that's when I got scared for my life," Bejar said. "I hit reverse on my car, rammed into 16th Street into oncoming traffic." 

Bejar said Harmon opened fire on him with his rifle.

Bejar said he couldn't stop Harmon, but he did get his license plate number and other information that helped police figure out who was responsible.

"I don't think that's right. Those guys didn't do anything to him," Bejar said. "That was just cold-hearted what he did."

Phoenix Mayor Greg Stanton called Bejar to thank him for his bravery.

Bejar said he wished he could’ve done more.