Two years ago, the pair of registered sex offenders cut the monitors from their ankles, hopped a Greyhound bus from California and holed up in a Las Vegas casino hotel until they were captured two weeks later. Released again, they were outfitted with new monitors, but, Orange County prosecutors contend, it didn't stop them from raping and killing at least four women. Federal and state officials said that after Estepp, 21, was killed, the devices worked as intended by pinpointing the locations of Cano, 27, and Gordon, 45. Orange County Senior Deputy District Attorney Larry Yellin said he had little information on whether the devices were used properly by state parole and federal probation agents who were monitoring Cano's and Gordon's movements. Last year, one Colorado parolee cut his bracelet but was not checked for several days, until he had fled and started a spree that claimed the lives of the state corrections chief and a pizza delivery man. In central New York state, audits showed federal probation agents ignored some warnings from a child porn suspect's bracelet for nine weeks, until he was arrested in the rape of a 10-year-old girl and the killing of her mother. State and federal officials said they would not give details of how the devices were used to track Cano and Gordon, citing the ongoing investigation.