Sex Offenders Arrested For Murder Wore GPS Devices During Killings, Police Say

Two registered sex offenders who were arrested last Friday in the deaths of four women wore GPS trackers while they committed the murders.

While investigating the suspects, Franc Cano and Steven Dean Gordon, police realized that information from their GPS trackers linked with cellphone records from the women they allegedly killed in the fall of 2013 in Orange County, California, the Associated Press reported.

"That was one of the investigative tools we used to put the case together," Anaheim Police Chief Raul Quezada said according to the AP.

The offenders were ordered to wear the trackers- Cano an ankle monitor and Gordon a GPS device- at all times as a condition of their parole. The two also checked in with police every 30 days, and gave updated addresses, photographs and fingerprints, Lieutenant Bob Dunn told the AP.

Cano, 27, and Gordon, 45, allegedly raped and murdered four women in October and November 2013 in locations known for prostitution while wearing the tracking devices. The pair was charged on Monday with four felony counts of special circumstances murder and four felony counts of rape, the AP reported.

Investigators are also looking into the possibility that Cano and Gordon committed more murders.

The police were able to "put a stop to a serial killing that would likely have continued beyond this point," District Attorney Tony Rackauckas said according to the AP.

The victims are Martha Anaya, 28; Monique Vargas, 34; Kianna Jackson, 20; and Jarrae Estepp, 21.

Anaya, Vargas and Jackson were at first thought to be missing when they were last seen in Santa Ana. But that changed in March when Estepp's body was found naked on a conveyor belt at an Anaheim trash-sorting facility. A joint investigation between Santa Ana and Anaheim police led to Cano's and Gordon's arrest.

Cano and Gordon were held without bail and are scheduled for arraignment on Tuesday, the AP reported. Both face life in prison or the death penalty if they are convicted.