CHICAGO (CBS) — It’s a problem we’ve been exposing for months – convicted sex offenders registered to bogus addresses.

Finally, a fix has come from an unexpected source. CBS 2 Investigator Megan Hickey spoke to the deputy US Marshal who took it upon himself to fix the fake addresses – overnight.

“I watched the story over and over again, and I slowed your story down to actually see the guys in this video and what their addresses were,” said Deputy U.S. Marshal Garrett Frieberg.

Frieberg was talking about our story from last week that caught his eye. We asked how and why sex offenders could get away with registering to a P.O. Box, or the Cook County Administration Building, or even the Dirksen federal Building, as their home addresses.

Nary a soul live in the aforementioned government office building or courthouse.

When we asked the Illinois State Police, the Attorney General’s Office, and local police, no one could give us a straight answer.

But then, Frieberg got involved.

“I did not know anything abbot these errors until I saw your stories, and once I saw your story, I was informed by my upper management and I took it upon myself to do what I could here at the Marshal service to correct these errors,” Frieberg said.

Lo and behold, the errors we uncovered nearly six months ago were fixed – with just one call from Frieberg to Illinois State Police.

Frieberg, who is a coordinator for sex offender investigations, tracked down the two offenders who were registered to the Dirksen Federal Building, 219 S. Dearborn St. He found one in the Kankakee County Jail and another in the Mississippi Department of Corrections.

The addresses should have been updated when they left the federal court.

“At that time, nothing was done to change them,” Frieberg said.

With more than 32,000 registered sex offenders in the state, Frieberg said errors are going to happen.

But he said it is important for all of the agencies involved in maintaining the registry and keeping offenders in compliance to work together to keep it accurate.

“Not only police or agencies know where they guys are living, but also the general public, for the safety of themselves and for their children,” Frieberg said.

Moving forward, the U.S. Marshals’ office said it is going to continue to go out of its way to fix any other wrong addresses we come across in the future.

Illinois State Police manage the database but have repeated told us the information is only as accurate as the data entered by local law enforcement of the Department of Corrections.

Megan Hickey