SACRAMENTO, Calif. (AP) - California parole officials have ordered increased monitoring of all sex offenders after several recent high-profile lapses.

The new policy requires parole agents to more closely track offenders' movements using GPS-linked ankle bracelets. It also requires agents to visit high-risk sex offenders at their homes one additional time each month.

The policy change memo obtained Friday by The Associated Press comes after agents were criticized for not learning convicted sex offender Phillip Garrido was allegedly keeping a young victim hidden at his Alameda County home for 18 years.

More recently, corrections officials are reviewing whether they should have revoked the parole of John Gardner, charged with killing one San Diego County teen and suspected of killing another.

Copyright 2010 The Associated Press.