MIAMI — When Baron “”Dirty”” Colon joined an MTV reality show featuring street thugs in 2009, he swore to reform or else wind up behind bars.

His own words may have proved prophetic: Police arrested Colon last week, charging him with the murder of a Miami area artist during a botched heist.

Colon, 24, of Miami Gardens, was a finalist on the second season of MTV’s “From G’s to Gents,” which offered $100,000 to the “”real”” gangster who most turned his life around. He competed against 15 contestants on the show, which claims to transform “”rough-around-the-edges young men”” into dapper, successful gentlemen.

He is charged in the January 2006 slaying of artist Marcelo Vera, and according to police was a suspect in the case even as he jetted off to Los Angeles to tape the show.

Investigators got a break last year when a confidential informant secretly recorded Colon confessing to intimate details only the killer would know, according to an arrest warrant filed in court.

Colon is jailed with no bond on charges of first-degree murder and armed burglary. He faces arraignment Jan. 28 in Miami-Dade circuit court.

“From G’s to Gents” is hosted by former P. Diddy assistant Fonzworth Bentley. The executive producer is actor Jamie Foxx.

In his show biography, Colon claims his mother threw him in the trash as a baby, and that she later died of a drug overdose. After stints in juvenile detention and foster care, he became a barber, Colon told the show.

A representative for MTV could not be reached for comment.

Colon’s criminal history shows arrests for drugs, grand theft and driving with a suspended license, but none resulted in felony convictions, court records show.

As a contestant, Colon and company were plunged into the posh world of a Los Angeles “”gentleman’s club,”” attending a wine-tasting, producing a public service skit for school children and even competing in a fashion contest.

“”I got two kids. I want to be in the gentleman’s club because I want to change, for them,”” Colon said in the opening episode. “”If I don’t change, there’s only going to be two things: prison, or death.””

But Miami-Dade police say Colon couldn’t escape his past. This is how the crime happened, according to a warrant prepared by prosecutor Matthew Baldwin and Detective Dalyn Nye:

Colon hooked up with a friend, Stephany Concepcion, 26, and two other men known only as “”Big Killer” and “”Crazy Dread.””

Their target was Vero, 44, of Kendall, Fla., who had employed Concepcion and had somehow angered her. The group plotted to rob Vero, who was known to keep large amounts of cash in his home.

Concepcion went to Vero’s house just past 11:30 p.m. and he invited her inside. From the bathroom, she called Colon to let him know the time was right for the robbery, the warrant said.

She heard a commotion from the other room, and then gunshots. She ran outside but her cohorts drove off, leaving her standing in the front yard as police officers rushed to the scene. Detectives arrested Concepcion. She pleaded guilty to second-degree murder, was sentenced to 15 years in prison and agreed to testify.

But investigators could not arrest Colon simply on Concepcion’s word. Detectives appear to have cracked the case when Colon was ensnared in an undercover cocaine investigation last year, after returning from the show.

An unnamed informant recorded Colon describing how he shot Vero as the man begged for his life, the warrant says. Colon also claimed one of the other men fired as well.

According to the warrant, Colon told the informant details “”ranging from the caliber of the weapons used in the homicide, the fact that the victim was a skinny male who put up a fight, and that he and (an accomplice) fled the scene and spent the night outside, even sleeping in the bushes the night of the murder to make sure he evaded police.””