Every time a big bust takes place by the police, the neighbors always appear on the news, claiming that they had no idea their neighbor, their buddy, could have done such a thing. Recently, when three young women from Ohio were found in a nearby house after having been abducted ten years before, the neighbor who helped rescue them was quoted as saying that he had known the perpetrator for years and had barbecues with him and had no idea he was capable of such a terrible act. Hindsight is 20/20, as they say, but obtaining the criminal records of a person before entrusting them with your valuables, children, or pet care to certain people is a good idea.
Naturally, you won't want to seek criminal records on a person on a whim; you won't use them to spy on your neighbors or harass people. But you will want to check out anyone who can affect your family or your job who you think might be suspicious. It's always a good idea to check the background of a prospective nanny or day care center, and you may also want to check out any online significant others before sending them any money.
A simpler form of finding free criminal records where you need them is in the case of registered sex offenders. By checking the sex offender list in your town, you can see who lives in your neighborhood who has been convicted of a sex crime, what that crime was, and how long ago that was. This way you can avoid allowing your kids over for trick-or-treating and teach them not to go in that person's house, assuming the charge was appropriate for that kind of action.
You can find free criminal records in a lot of different places on the Web, and often, they're instantaneous. They're not always perfectly accurate, so be wary of where you're going, but criminal histories are a matter of public record and it is your right to access them when you need to, and often you can get them for free. When your safety is on the line, it's worth checking out.