The two spent most of the night being questioned at the police station in Hemet and now both are charged in Rios' murder.
Officials said that the two fugitives had been living in Mexico for more than a month. Federal marshals worked with Mexican authorities to track and arrest the fleeing couple.
"This has been a significant case for the city of Hemet. We've got a child that was brutally murdered," described Hemet Police Chief Richard Dana.
Dana said that the two suspects were arrested by Mexican authorities then turned over to the U.S. Marshals. He says the two were getting help during their time in Mexico, but he wouldn't elaborate.
"People have to have help to get food, to have shelter, to have some place to stay, and by tracking those things, we were able to locate where the people were," Dana explained.
They are suspected in the death of Rios, who was shot, cut up and set on fire in an attempt to conceal the crime. Rios' charred remains were found in a shallow grave in the backyard of Campos' home on the 1400 block of Bluejay Way on Nov. 18.
Police said they believe Rios was murdered the night of Nov. 15 or early Nov. 16, with a total of six people present during or just after the crime. Police following up on a missing-persons report filed by Rios' mother and a tip from a neighbor searched the Bluejay Way home and found human remains in the backyard.
Police also found a machete, butcher knives, a bullet casing, burnt clothing and an empty gas canister at the home, as well as drag marks in the backyard.
Campos, who was named in a $2 million warrant disappeared the night after a huge bonfire was spotted at a home on Nov. 15. Neighbors reported a powerful stench emanating from the Sunday night bonfire, which was set after several people reportedly gathered at the house to watch a football game, according to police.
Campos had lived in the home for a few months with his parents, but neighbors said the family moved out about a week before the bonfire.
Sharp, who was initially reported missing the same time, had been questioned early in the investigation and released. She then disappeared.
The mother and stepfather of Jose Campos were detained in December but were never charged.
City News Service contributed to this report.