It began, police say, with a stunning act of betrayal. Teenager Luis Mir set up the heist of over $600,000 of his uncle’s cash, stored in a safe inside his own family’s West Perrine home.

That led to a bizarre chain of events that ended in an amateurish but brutal kidnapping, a night of vicious torture and Mir’s half-naked escape through the streets of South Miami-Dade.

The final violent plot twist: Miami-Dade detectives, rushing to the rescue, fatally shot Damaris Jaramillo, 21, a kidnapper’s girlfriend who brandished a revolver as police stormed the hostage stash house.

The previously unknown back story of the outlandish tale of greed and violence is laid bare in police files released last week in the pending criminal cases against the alleged kidnappers.

Awaiting trial: Alain Perea, 19, Roman Villacres, 19, Dexter Marshall, 27, Carlos Morillo, 26, and Joe Manuel Cotte Vazquez, 18. They have all pleaded not guilty.

The men are charged with armed kidnapping, conspiracy to kidnap and felony murder. In Florida, someone who commits a felony in which someone dies can be held responsible for that death.

The ringleader, according to investigators, was Perea, a South Dade High dropout who was out for vengeance against Mir, not just for a double-crossing in the safe cash grab, but seemingly also because Mir repeatedly flirted with his girlfriend.

Perea’s lawyer, Fred Moldovan, said it was too early to comment. “We’re still trying to figure out what happened in this case,” he said.

The drama revolves around Mir, 19, a former student at West Kendall’s John Ferguson High. While he was the victim in the kidnapping, Mir is also a defendant after his unrelated arrest in March for burglary, grand theft with a firearm and criminal mischief.

Early last year, Mir met Perea through a mutual friend, Miguel Romero. In May 2012, he told them that his uncle, who was involved in marijuana grow houses, had $300,000 stashed in a safe at the family’s South Miami-Dade home.

And with his uncle in Cuba at the time, only his grandmother and 8-month-old baby sister would be inside the house.

“He told us all the little information, every detail about his uncle, his family,” Perea said. “Where it was located and what time to go in, who was inside the house, everything. He told us the coordinates.”

With Mir waiting a few blocks away, the band — wearing masks — broke into the house. Perea and Villacres pushed away the grandmother and lugged the heavy safe into their van.

Back at Perea’s house, the group used a piece of iron to smash the cheap lock. Inside: about $640,000 in neatly organized bundles.

They decided to split it evenly. But Mir wound up keeping most of the money, the youths believed.

Mir told cops he took only his fair share. To relatives, Mir feigned surprise at the burglary — but they grew suspicious when he soon showed up driving a gray 2010 Infiniti.

Mir was unemployed.

After the heist, Mir and Perea stopped talking. Word soon got to Mir that Perea was “surveilling” him.

“I didn’t pay him no mind,” Mir said.

But the opportunity for revenge presented itself Aug. 8 at a teen pool party hosted at a South Miami-Dade apartment complex attended by Perea’s girlfriend. Halfway through the party, Mir and a friend, Xavier Valdes, 17, of Ferguson High, drove to a nearby McDonald’s for ice cream.