Roman Cerratos was accompanied by an FBI agent to the United States. He was turned over to the Los Angeles County Sheriff's Department after he arrived to Los Angeles International Airport Friday from Guadalajara.
Video from onboard his Alaska Airlines flight shows Cerratos in handcuffs while law enforcement officers walked in front and behind him.
The search for the two suspects in the murder investigation triggered an Amber Alert in April for Alora Benitez, who is now 16. She was last seen with her mother, Maricela Mercado, and Cerratos, who are each wanted in the Carson murder of Jeffery Appel.
MORE: Search for teen continues after Carson murder suspect flees with daughter
Cerratos and Mercado were last seen driving a white 2013 BMW four-door sedan with Nevada license plate MARIMAR. That vehicle was later recovered unoccupied in San Diego in late April, according to the Los Angeles County Sheriff's Department.
Authorities are still searching for the 15-year-old girl and Mercado, investigators tell Eyewitness News.
"We had information that they worked together at some point in Colima, Mexico. We believe they also had traveled from Vallarta, Mexico. At this point, their whereabouts are unknown. We're hoping that this media attention... that she'll take note of it and maybe surrender, turn herself in to a consulate or embassy in Mexico," said FBI agent Scott Garriola.
The FBI is not saying how Cerratos was captured.