When Joe Saenz walked up to a Whittier, California-area home in the summer of 2008, a surveillance video shows he was smiling, rubbing his hands together and greeting associates, according to authorities.

On the streets he was known by the nickname "Smiley," and his demeanor that day fit that handle -- right up until he reached the front yard of the home.

That's when, the FBI and police say, he drew a gun and shot one man several times in the head, execution-style. The slaying, caught on video, was over drug money, authorities believe.

It was not the first murder Saenz was accused of. Authorities also say that in 1998 he killed two rival gang members and kidnapped, raped and killed his girlfriend.

The FBI placed Saenz on its 10 Most Wanted Fugitives list in 2009. Authorities suspect he later became a hit man for a Mexican drug cartel.

Despite being featured on the "America's Most Wanted" television program and on the websites of the FBI, the Los Angeles Police Department, and the Los Angeles County Sheriff's Department, Saenz eluded arrest for 14 years.

On Friday, authorities announced his capture in Guadalajara, Mexico, after a tip led officers to his location. "The adage that you can run but not hide speaks truthful here," said Bill Lewis of the FBI's Los Angeles field office.

During a news conference Monday, Lewis said Saenz was arrested by Mexican authorities without incident on the second story of a modest apartment building above a beauty salon.

He said the $100,000 reward that had been offered for information leading to Saenz's arrest will be paid but he declined to identity the source of the tip.

"Surveillance of the vicinity and attempts to arrest him went on for several weeks," Lewis said. "With the assistance of our Mexican law enforcement partners, we were able to take him into custody."

Saenz was flown Friday to Los Angeles, where he faces the multiple murder counts.

Before authorities discovered the video of the 2008 killing, Los Angeles police detectives theorized Saenz might be dead.

The grisly crime scene in Whittier, about 20 miles east of downtown Los Angeles, indicated to Los Angeles County Sheriff's Department Detective Traci Gonzales there were drug and gang ties to the slaying, so she showed the video to Los Angeles Police Department Detective Ron Chavarria, a veteran on the gang beat.

With that, the videotape broke open a case that had frustrated local and federal authorities for more than a decade. Now detectives knew Saenz was still out there.

Police say Saenz was a member of the Cuatro Flats gang in the Hollenbeck area of Los Angeles, where he grew up and where 34 gangs fight over turf and drug trafficking. He stepped into police cross-hairs in 1998 after the fatal shooting of the two rival gang members at a housing complex.

Then, police say, he was a fresh-faced 22-year-old with a dark side.

"Just gruesome, gruesome, cold-blooded," detective Chavarria said. "Just walks right up to these guys, shoots them and then just walks over and stands over them and shoots them each in the head and casually walks away."

Police made his capture a priority.

"We had pictures of him constantly on our dashboard so that there was no question if we saw this guy we knew who he was," said Chavarria, who spent time with a gang patrol unit in the neighborhood.

Within two weeks, Jose Luis Saenz -- known as Joe, Louie Louie and more than two dozen other aliases -- was wanted for a third murder.

Investigators say that on July 25, 1998, after hearing that Sigreta Hernandez, the mother of his child, would turn him in for the double killing, Saenz kidnapped, raped and murdered her at his grandmother's house.

"He leaves a note indicating that his grandmother has nothing to do with the murder and that he left the scene. And from that point on he became a fugitive," Gonzales said.

Authorities believe Saenz moved up the hierarchy from local gangs to international drug trafficking, crossing the border with falsified documents.

Los Angeles County Sheriff's authorities said Monday the motive for the 2008 murder was $500,000 in cash earmarked for Saenz that authorities seized during a traffic stop involving an alleged associate of Saenz.

As a fugitive, Saenz is suspected of traveling through Mexico, Central America, Canada and the United States while trafficking in narcotics. "He was quite an affable character who masked his identity to elude authorities, Lewis said.