MINNEAPOLIS â When her 11-year-old son Jacob was kidnapped by a stranger in a mask holding a gun, Patty Wetterling wanted to know how this could have happened. What did the cops need to catch predators that they didn't already have? That was 1989, and her questions led to the creation of Minnesota's first sex offender registry in 1991. Back then, it was a private list designed to quickly show law enforcement if convicted sex and kidnapping offenders lived in an area by requiring them to register their addresses. Thirty years later, Minnesota's list has swelled to more than 18,000 active registrants, including juveniles, some not much older than Jacob was when he was kidnapped. Meanwhile, the name of Danny Heinrich, the man Wetterling learned 27 years later kidnapped and killed her son, would have never landed on that list because he hadn't been charged or convicted of a sex crime before Jacob.