Troy Graves, the serial rapist who terrorized women in Center City and Fort Collins, Colo., was flown to Colorado yesterday to begin serving a life sentence for the crimes he committed there.

Graves, 30, an Air Force enlisted man, was transferred to Colorado in keeping with plea bargains in both states. During a hearing last week in Common Pleas Court, Graves admitted to being the man known as the Center City rapist and strangling Wharton School graduate student Shannon Schieber, 23, during a 1997-99 spree in which he assaulted six women inside their homes. In exchange for his guilty plea, for which he received a life sentence plus 60 to 120 years, prosecutors agreed to not seek the death penalty and to let him serve his time in Colorado. In Colorado, Graves received a life sentence on May 17 after admitting to attacking seven women beginning last year near the campus of Colorado State University.

A spokesman for the Philadelphia Sheriff's Office said Graves was placed aboard a United Airlines jetliner without incident yesterday. He arrived in Denver shortly after noon local time and will spend up to a month at a diagnostic center before officials decide which prison he should be sent to, a Colorado Corrections Department spokeswoman said.

Graves was arrested in Fort Collins in April after police used DNA evidence to link him to a string of similar attacks on women near the Colorado State University campus.