When a sex offender in Kansas moves from the state and doesn’t register his new address, he becomes the concern of the U.S. Marshals Service, which enforces sex-offender laws across state lines.

It’s common for sex offenders to not re-register when they move, as a Journal-World investigation last September found. According to the report, more than 160 Kansas sex offenders did not register in their new state, and, depending on the state, that could be a federal or state crime.

The Journal-World provided the Marshals Service with the list it had compiled for Kansas, and over the past several months agents have been tracking down the sex offenders who have failed to register in their new state.

The Marshals Service found some of the offenders had died or moved to states with different registration laws that did not require them to register.

What is left is a list of 22 cases, four of which have led to arrests for other offenses, and the suspects could face additional failure-to-register charges. Two others are serving in the U.S. Army, which, according to the Marshals Service, is aware of both men’s sex-offender status.

The Marshals Service is searching for several other offenders who have failed to register.

The Kansas Bureau of Investigation, which is responsible for the Kansas Sex Offender Registry, sends letters to states notifying them that a registered sex offender is entering their state. But after that, it’s up to the other state and the offender to make sure they comply with the new state’s law. If there isn’t any communication, neither the state nor the Marshals Service would be aware of the sex offender’s status.

As Laura Ahearn, executive director of Parents for Megan’s Law and the Crime Victims Center, a nonprofit organization that advocates for more accountability in sex offender registries nationwide, says, “We’ve established a law that requires society’s most cunning of criminals to register on an honor system.”

The Marshals Service spent valuable time tracking down the 160 names on the Journal-World’s list, basically picking up the states’s slack. The service should be commended for its work.

Now it’s time for a national sex offender registry and a unified reporting system. Inconsistent laws among states make keeping track of sex offenders too complicated, which, in turn, endangers an uninformed public.