Mayor Becker was arrested by the state Division of Criminal Investigations. DCI runs the Internet Crimes against Children Task Force unit, which conducts Internet sex stings on computer users. Basically, they pretend to be underaged girls looking to have sex with older men. When the men respond, agents arrest them at a meeting point.
That may not be what happened here, but the fact that DCI is involved doesn't look good.
Update: The J-S confirms DCI's Internet sex sting unit was involved.