A state audit of sex offender registration laws finds a good many offenders are avoiding an obligation calling for them to make known their residences on a regularbasis. State Auditor Claire McCaskill says all sex offenders face certain registration requirements – they must make known their residence at least once a year. But, the rules are more strict for violent sex offenders and for those who have abused children. They are required to reconfirm their addresses every 90 days. Many of these offenders are not bothering to do that. McCaskill sayspart of the problem lies in the fact there is no central registry of sex offenders, making it harder to keep track.