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This is part of a regular series that profiles America's most wanted criminals.

A couple of armored guards were on their daily morning routine after the Thanksgiving weekend of 2004, picking up holiday receipts at a multiplex theater in Greater Phoenix.

One guard stayed inside the vehicle while his partner, Keith Palomares, went inside to get a bag containing $56,000 in cash.

As Palomares, 24, walked out of the theater in Ahwatukee, Ariz., a man wearing a black hooded sweatshirt ambushed him, firing a .45 caliber handgun at his head. Five of the six bullets hit their target, killing Palomares.

The gunman then grabbed the bag of money and fled on a bike.

"It was an assassination," says Lance Leising, an FBI special agent in the Phoenix bureau.

Police recovered the bike and dusted it for fingerprints. They came back positive for a man named Jason Derek Brown.

Brown didn't fit the image of a harden criminal. Handsome and with highlighted blond hair, he looked more like a surfer dude from Orange County, Calif., where he grew up.

Those who knew him say he boasted of a privileged lifestyle, filled with beautiful women, expensive cars and vacations at luxury resorts.

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But officials say Brown was a desperate man who had defaulted on at least one large loan and was racking up tens of thousands of dollars of debt to pay for his extravagant lifestyle.

"He tried to look like he had a lot of money, but he never did," Leising said.

Det. Paul Dalton of the Phoenix Police Department said Brown defaulted on cars, boats, houses and rental agreements.

He said he would go to a car dealership, sharply dressed and clean-shaven, and buy a car using a false Social Security number and address.

"If you look at the guy and kind of imagine yourself as him approaching you, you wouldn't think in two seconds that he was a murderer, he's that type of person," Dalton said.

"When he does get arrested, you're going to sit back and say 'I never knew.' "

Dalton said Brown picked Phoenix to carry out his scheme.

"He picked a big city. He did his scamming," said Dalton. "When [the money] started going dry, he had this ultimate plan."

Police say Brown was living in a hotel close to the multiplex, and witnesses say they saw him casing the place days before the murder. Earlier that month, records show that he bought a Glock semi-automatic 45-caliber pistol and took a firearms class in Salt Lake City.

Police were able to link the ammunition used in Palomares' murder to the bullets Brown purchased when he bought the gun.

Clark Aposhian, Brown's instructor, told America's Most Wanted that he was "an obnoxious student" who was inexperienced with firearms.

In fact, investigators found a witness who said that days before the shooting, Brown accidentally shot his pickup truck during practice shooting. The witness told police that Brown apologized and paid him about $300 to repair the truck.

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Investigators say they have evidence linking Brown to the crime, but the trail leading to his arrest has turned cold.

They know Brown used his BMW as a getaway car and fled to Henderson, Nev., where he deposited $2,000 in cash into his bank account the next morning.

Brown then traveled to Las Vegas, police say, and swapped his BMW for a black Cadillac Escalade he had in storage. He moved on to Orange County, Calif., and stayed there with family and friends until Dec. 6, 2004, when FBI agents carrying a warrant for his arrest missed him by only an hour.

About a month later authorities recovered Brown's Cadillac in the long-term parking lot at the Portland International Airport. Investigators believe that, while in Portland, he mailed a package containing clothes and golf equipment to his brother in San Diego.

"He has been a ghost since then," Leising said.

Click here for Brown's Most Wanted poster.

Brown is 5-foot-10, 170-pounds, with blond hair and green eyes. He speaks French fluently, loves to go out drinking and doesn't have close ties to his family, except for his brother.

He enjoys skiing, snowboarding and riding dirt bikes and ATVs. His keeps his house extremely clean and requires visitors to remove their shoes before entering.

Dalton said Brown is likely living in a big city where he can blend in. "He's that type of person where you wouldn't second-guess that he's not the person that you think he is," Dalton said.

He is believed to be using aliases that include Jason D. Brown, Derek Brown, Greg Johnson, Harline Johnson, Greg Harline Johnson, John Brown and Jay Brown.

Brown is wanted for unlawful flight to avoid prosecution, first-degree murder and robbery.

The FBI is offering a $100,000 reward for information leading to his arrest.

Click here to find the phone number to your local FBI office.

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