Despite registries to track sex offenders within the U.S., law enforcement agencies aren’t paying close attention to such individuals when they traveling abroad, leaving children overseas potentially vulnerable to new attacks, a congressional watchdog warns.

“In recent years, certain individuals who had been convicted of a sex offense in the United States have traveled overseas and committed offenses against children,” the Government Accountability Office said in a report requested by several members of the House Judiciary Committee.

In fact, sex offenders are often not required to report planned international travel in some law enforcement jurisdictions, or are expected to self-report that information without much verification from authorities, the GAO said.  Out of 50 jurisdictions surveyed by investigators, 22 reported they don’t require sex offenders to provide advanced notice of international travel.

Many law enforcement agencies get information on sex offenders’ travel plans from U.S. Customs and Border Protection, but that data is reported voluntarily by several transportation sectors.  So the government doesn’t always have accurate information on “individuals who leave the United States by commercial bus, private vessel, private vehicle or by foot,” investigators said.

In addition, the law enforcement agencies – including the U.S. Marshals, FBI and Immigration and Customs Enforcement (ICE) – are largely dependent on foreign agencies to notify them when a sex offender is returning to the U.S., a notification they don’t always send.  And when they do, it can be limited. 

“The information these officials provide is based on anonymous tips or offenders’ self-reported information,” the GAO said.

Federal agencies are trying to address some of these concerns by developing an interagency notification system to alert law officers when sex offenders are preparing to travel.  This “will help law enforcement officers to avoid using resources to search for sex offenders who they thought had absconded, when the offender had actually left the country on personal travel,” the GAO said.  The system is expected to be online by next month.

But investigators noted that the system again relies on Customs and Border Protection data, and since that information is incomplete, some sex offenders might still slip through the cracks.

“The fact that the automated notification will not address all limitations will likely remain for the foreseeable future because they are inherent to well established processes for entering and exiting the country,” the GAO said.

The updates are also to help unify domestic information sharing.  Between August 1 and September 31, 2012, ICE sent out 118 notices about sex offenders traveling internationally.  The U.S. National Central Bureau sent out 123 notices.  But the two agencies only overlapped on reporting 18 cases; the others were all cases at least one federal agency had missed.  GAO investigators said the two agencies need to work together to ensure they’re kept on the same page and are sharing information.

And ICE hasn’t requested to be a part of the new updates, saying it only needs data on sex offenders that it watches for its mission to combat the sexual exploitation of children.   But investigators said ICE officials need to take a hard look at whether the benefits of getting the interagency notifications are going to outweigh the costs of linking into that system.

The Homeland Security Department – ICE’s parent organization – said it would look into joining the alert mailing list.  But spokesman Jim Crumpacker said ICE has a specific mission to combat the sexual exploitation of children that might not be helped by the interagency alerts.

“If the registered sex offender is exiting the United States, the automated notification received by ICE would have to first be vetted to determine if the traveler’s offense was against a child,” Crumpacker said.

Meanwhile, the Justice Department’s INTERPOL Washington office, the U.S. National Central Bureau, said it is already working with ICE officials to improve information sharing.

“Even in these times of severly restricted budgets, INTERPOL Washington considers this program to be a priority,” office director Shawn Bray said.

The GAO said the government must maintain constant vigilance about the travel plans of sex offenders.

“Cases in which individuals who had previously been convicted of a sex offense in the United States subsequently traveled overseas to commit an offense against a child underscore the importance of sex offender registration and notification standards to help ensure public safety in the United States and abroad,” the GAO said.