Franc Cano, 27, was arrested on the 5100 block of East La Palma Avenue in Anaheim around 6:05 p.m. Friday. Steven Dean Gordon, 45, was arrested shortly after.
Police say the transients, both registered sex offenders, allegedly murdered three women who frequented the same area in Santa Ana and mysteriously disappeared last October. Their bodies have not been located.
The suspects are also linked to the murder of a woman whose body was found at a trash recycling center in Anaheim in March.
Santa Ana police say three of the victims disappeared along a half-mile stretch of First Street between Grand Avenue and the 55 Freeway.
Kianna Jackson, 20, was the first to disappear on Oct. 15. Two weeks later, Josephine Vargas, 34, vanished. On Nov. 12, Martha Anaya, 28, disappeared.
Police had entered the three women in the National Missing and Unidentified Persons System and had also been checking jails, hospitals and morgues for any signs of them.
"It's so hard for my family, so hard for my sister. We've been doing a lot of things to find her, and now we found her dead," said Anaya's aunt, Angelica Salcedo. "It's so hard, there's no word to explain the pain."
On March 14, a female's body was found at a trash recycling center on a conveyor belt that sorts trash in the 1000 block of N. Blue Gum Street.
She was later identified as 21-year-old Jarrae Nykkole Estepp. Investigators say her naked body was facing down and partially covered in trash.
The suspects allegedly targeted the victims because of their ties to prostitution and escort services.
Anaheim police say both suspects were required to wear GPS tracking bracelets as a requirement of their conviction.
A press conference will be held Monday at 4 p.m. regarding the arrests.
The investigation is ongoing. Detectives say there may be more victims in and outside of California. Anyone with information on the case was urged to contact Orange County Crime Stoppers at (855) TIP-OCCS.