Patricia McKay, 68, was killed outside a mall in Newport Beach during an attempted robbery when she was hit by one of the offenders' cars.
Witnesses said two robbers appeared to be after her husband's watch, but turned their attention to her bag. Her husband was Doug McKay, a former chair of the BNZ board. They were both friends of Prime Minister Christopher Luxon.
As they fled the scene, Patricia was hit by a vehicle driven by a third offender.
Local man Beau Bayless said he was minding his own business on Tuesday afternoon (local time) when he "heard some excitement coming from down the street".
"That poor woman was out in the middle of the street, basically fighting with two guys over her purse, and I was still a ways kind of down the street - several hundred feet," he told RNZ's Morning Report.
"So when I saw that, I just - something said 'she's going two vs one, that could be someone's mom, someone's grandma' - it could be mine.
"So I ran over to try to help, and that's when they hit her the first time and she went down, and I'm still trying to get to her and then one of them got into the car.
"So there was two in the car and one still outside of the vehicle - and that's when they ran her over, and her poor husband was sitting there in just absolute shock. My heart goes out to all of them, like, I feel so bad."
With the car moving, Bayless suspected the two offenders inside had made a call to ditch the scene, leaving the third behind.
"I knocked him down and I went down as well and then there was a scramble. He was running for the car, I was running after him. I just wanted to get a hold of one of them, you know, for what they did to that poor woman."
Bayless managed to get his hands on the suspect, but then heard gunfire.
"We were still running, and that's when I heard the first crack and it whistled past both of our heads and I thought, 'Hmmmm, that sounded like a gunshot.' And then he ducked out of the way and I saw his buddy out the passenger side, gun pointed at me, and he fired two more at me and I hit the deck. I had to let the guy go."
"When I popped my head up, the guy that I was trying to get to the ground was just getting into the car, and I knew I'm not gonna go rush into the car that they were just shooting [from] - that's bad news bears.
"So I picked up a rock and I tried to throw it at the car so I could mark it somehow and say, 'Hey, it was a white Camry that has damage to the rear end because I threw a rock at it' - but I missed."
"I'm not a medical professional, but I've seen some things in my life and it was bad. It was really, really bad. So I don't think very many - even younger healthier people - could have survived that trauma."
Bayless said if he was not getting shot at, the offenders might not have got away.
"When I was getting shot at, that's when I was like, 'If I get shot, my wife will kill me.' So that was about my biggest thought during the whole interaction. I just wanted to try to help.
"I felt terrible for her, and then when I saw what they did, I wanted to get a hold of one so they could answer for that. It was just senseless and horrible and no one should have to experience that."
Following a police chase, three men were arrested and charged with homicide, robbery with a firearm and criminal conspiracy.
Bayless said he had never seen anything like it in the area.
"If you're in contact with the husband and the family, please let them know," he told Morning Report. "I'm so sorry I could not - I tried to do the best I could. I really wish I could have done more and my heart goes out to him."
