HARRISBURG - Several hundred sex offenders had not registered as required, and some are still missing, according to an audit released yesterday of the Pennsylvania Megan's Law by the state Attorney General's Office.

Many other records also were improperly kept and had to be revised to reflect the Megan's Law conviction, the audit said.

The audit found that 369 released offenders were obliged to register but had not, although 47 were dead and in 11 cases the county prosecutor declined to pursue the process to compel registration.

There are outstanding warrants for 18 offenders who did not register.

The audit covered a 10-year period ending in December 2005, but in future years it will be conducted annually.

In 401 cases, a sex-offense conviction was not properly recorded in the offender's files, but 335 were in prison or jail - and so not yet required to register - and the other 66 had died or been deported, the audit said.

The Attorney General's Office recommends that offenders register when they are sentenced rather than at the time they are released from prison or jail. It also suggests that specific court, jail and probation officials be assigned to periodically update sex offenders' records to keep them current for Megan's Law registry purposes.

"Then there's no doubt who's responsible for doing it," said Nils Frederiksen, spokesman for Attorney General Tom Corbett.

The office is calling for better technology to help agencies communicate about sex offenders' case information, expanded information available to the public on the Megan's Law Web site, and an updated law that would require more intensive registration.

To read the Megan's Law audit, visit the attorney general's Web site via http://go.philly.com/corbett