The 51-year-old Iraq War veteran who fearlessly rushed the California synagogue shooter, said Tuesday he acted on instinct when he heard gunshots ring out during services at Chabad of Poway on Saturday morning.
Oscar Stewart said he had intended to get up and run like the rest of the congregants but something stopped him.
"I took maybe one, two steps and... I don't know why, I turned around and ran towards the gunfire," he told "Fox & Friends."
Stewart confronted the suspect who authorities have identified as 19-year-old John T. Earnest wearing a military-style vest and wielding a semiautomatic rifle.
"As I ran toward him, I yelled out as loud as I could, every inch of my body mustered this noise," he said on Fox News. "He looked at me and had a look of like fear. He dropped his weapon to his side. He had a tactical sling so it didn't fall to the floor... he turned around and he ran out of the building."
Stewart started chasing him.
"I was trained that if a person has a rifle and you are within a certain number of feet, they can't deploy the rifle against you," he said. "...I kept in pursuit. As soon as he jumps in his car he raises his rifle. I punched the car as hard as I could and he puts (the rifle) back down. He starts the car and at this moment I hear in the background, 'I have a gun, clear out. Get back.' I fall back and Jonathan Morales... a Border Patrol agent opens up with five rounds into the car."
He added: "(Morales) shot at a parked car and we were trying to keep the guy from going anywhere."
Stewart said once the suspect was subdued, he ran back inside the synagogue to help the others. That's where he saw Rabbi Yisroel Goldstein bleeding from his hand and congregant Lori Gilbert-Kaye lying on the ground. Stewart said he got some help and flipped Gilbert-Kaye over, before a doctor who had been nearby started doing chest compressions while he breathed into her mouth.
"At some point he (the doctor) got tired," he said. "I started doing both the compressions and the breath."
Unfortunately, Gilbert-Kaye, 60, died in injuries she sustained during the shooting. She is said to have thrown herself in front of the rabbi, possibly saving his life.
Stewart told Fox News that he's feeling emotionally fine but that his wife, who was widowed by her first husband, is having trouble coming to terms with the incident.
"My wife is actually stressing out more than I am," he said.