Los Angeles (CNN) -- 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.
While he avoided capture for years, Saenz reportedly made statements that he planned to kill a police officer if they ever found him and arrested him, according to the FBI's Most Wanted Fugitive website.
During his flight from Guadalajara to California over the weekend, authorities say, Saenz bragged about his extensive travel, including to the Los Angeles neighborhood where he was first indoctrinated into a gang, and to Los Angeles Laker pro basketball games.
"We heard rumors that not only citizens were afraid of him, but also his own gang members were afraid of him," detective Chavarria said.
The arrest of Saenz involved a multiple-agency task force that includes the Mexican National Institute of Immigration, the Mexican attorney general, the FBI's legal attache in Mexico City and its sub-office in Guadalajara, Mexico, the Los Angeles County Sheriff Department and the Los Angeles Police Department.
"It was in the endless perseverance of the hunt and continued efforts over the past decade that led to his capture," said LAPD Deputy Chief Michael Moore.
At Monday's news conference, Chavarria described Saenz as a calculated cold-blooded murderer who is more intelligent than most gang members.
But it was the chilling video that put him on the FBI's Most Wanted list, the detective said.
"He always seemed to stay one step ahead of us," Chavarria said. "It looks like he really enjoys what he does, he enjoys killing people."
Saenz was scheduled to be arraigned Monday in Pomona County, California, for the 2008 slaying and the 1998 death of Hernandez. On Wednesday he will be arraigned for the two other 1998 shooting deaths, authorities said.
CNN's Kara Finnstrom contributed to this report.