Jose "Joe" Luis Saenz reportedly killed four people, including the mother of his child.
A news conference will be held at 9 a.m at the FBI headquarters on Wilshire Blvd, where authorities will speak about his capture.
Saenz was known on the streets as "Zapp," "Peanut Joe Smiley" and "Honeycutt," among other aliases.
He was arrested in Guadalajara late Thursday and arrived at Los Angeles International Airport about 7 p.m. Friday.
He had been listed among the FBI's Ten Most Wanted fugitives since October 2009.
"He was very difficult to find," said Laura Eimiller of the FBI. "It took a lot of determination."
Saenz is suspected of killing two rival gang members -- Josue Hernandez and Leonardo Ponce -- on July 25, 1998 as payback for an attack on an associate.
According to the FBI, Saenz later kidnapped, raped and murdered his girlfriend Sigrieta Hernandez, the mother of his child, after she threatened to turn him in for the July 1998 killings.
Authorities said they also have video of Saenz killing Oscar Torres in October 2008 in Whittier over a $600,000 drug debt.
Saenz, a Los Angeles native, is also expected to be charged with unlawful flight, in addition to the murders and various other crimes.
A $100,000 reward had been offered in the case.