LAS VEGAS -- Easter Sunday in Sin City turned into a whole lot more than two retired Cowtown cops ever expected.

Heidi Tiwater and Paul Kratz were longtime investigators with Fort Worth police, serving for more than 65 years combined.

"We've definitely seen our fair share," said Kratz.

But what they hadn't seen until Sunday was a man armed with a knife terrorizing folks on South Las Vegas Boulevard.

"I thought he was just a teen, so I'm thinking I'm just gonna tackle him," says Tiwater.

Around 3 p.m., the couple stopped by the World Famous Gold and Silver Pawn Shop, the tourist attraction from the popular reality show Pawn Stars.

After snapping some photos, they headed directly next door to Jared's Old Fashioned Hamburgers, and that is when the trouble started.

"We were sitting out on patio," says Kratz. "Then, I heard her yell and saw a blur and a guy was running off, and she was screaming about her purse. We both took after him."

The couple chased the suspect through a parking lot and across the heavily packed strip as he darted in and out of traffic.

"What I didn't know was he had a knife and had robbed some guy in the bathroom just before," Tiwater says.

The suspect, later identified as Brandahn Green, jumped into a parked taxi after crossing the busy street.

The retired cops surrounded the car, as did staff from the restaurant and security guards from the nearby pawn store.

"He had the knife [...] looked at me and said 'I'm gonna kill you.'  And that is when Paul hit the window with his hands," says Tiwater.

It proved enough of a distraction that she was able to reach through the window and snatch back her purse.

But Green suddenly jumped out of the cab and started threatening people, according to Kratz

"He was waving the knife. It was definitely a deadly weapon," he said.

Green briefly took off again but seemed to slow down when he heard sirens blaring as Las Vegas police swarmed the scene.

It wasn't long before the man was in handcuffs, while the retired cops trudged back to finish lunch.

"We got a free dog. One of the stars from the show came over and made sure we were okay," says Tiwater.

Green is being held on robbery and assault with a deadly weapon charges at the Clark County Jail.