Shirley Rupp, the Tucson grandmother who was caught on surveillance video tangling with a purse snatcher, says she was not about to let someone run off with her wallet.

"I work really hard for my money, and you just can't let people take things away from you, so I didn't," Rupp says.

A surveillance tape caught the New Year's Day encounter outside a Subway restaurant in Tucson, Ariz., showing the spry grandma yanking the man by the hood of his sweatshirt and then scuffling with him for her purse. Until her exclusive interview with ABC News, Rupp's identity had not been made public.

"It was total reaction, I was walking to my car from Subway and all of a sudden he was behind me. I just thought he was so close that I grabbed his jacket, and then he tripped. And evidently dropped my wallet, " said Rupp, 64, a real estate agent who has six grandchildren.

Shirley Rupp is seen in this undated photo provided to ABC News : Courtesy of Shirley Rupp

Rupp didn't realize what a brawl it was until she saw the tape of the event with her own eyes.

"I didn't realize really why I am so sore, but then I saw the video. My friends, and even me, are shocked that it was me. I am a very peaceful person. It's out of my character to react like that. I don't even watch action movies," Rupp told ABC News.

Attempting to wrangle her purse back, she left the robber scrambling to his feet, dropping her wallet, and fleeing in a green Honda Civic with tinted windows, Deputy Tracy Fuitt of Tucson County Sheriff's department says.

"Now I am a pretty fast runner for a little distance, but I had on flip flops," Rupp says.

Before the attempted robbery, Rupp says she wanted to help the man.

"We have a lot of homeless people here, and he just looked like that. I thought maybe I'll ask him if it's okay if I can give him a sandwich. But then I caught his look that seemed kind of mean, so I said to myself I'm not going to," she said.

Ryan Riehl, 19, an employee of the Subway restaurant, had noticed the suspect prior to the incident.

"I saw this guy get out of his green Civic car and walk into the plaza. He had a black sweatshirt and jeans, and his hood was up. You basically couldn't see his face," Riehl says.

Moments later a fellow employee heard screams and sent Riehl outside to see what was going on.

Ryan also notes that Rupp looked like she was in pretty good shape.

"She was in her workout suit," he said.

Rupp told ABC News that she has a regular workout regimen that combines cardio and weights at her gym, which was located in the same strip mall where she toppled the crook.

"I attribute handling the situation a bit to my free weights and elliptical-ling," she said.

Nine days after the confrontation, Rupp says she finds herself reflecting back on the incident.

"You do kind of start having flash backs of it. You think, oh my gosh, he could have had a gun or a knife, or anything. I certainly am not carrying my purse under my arm anymore. I am probably more aware of things," she said.