Free background checks are possible to the extent that you can enter the subjects name and positively identify that records are available. The free background check (preliminary checks) will not give you more than verification of records available. Free background checks are generally not as comprehensive as the paid background checks.
Web sites that claim that they offer completely free background checks, are not being completely honest. An accurate and thorough background investigation takes time, and lots of it.
A free background check service gets thier information from a number of public record databases. These records will contain a subject's name, birth date and address. A comprehensive background check will often have civil, criminal, traffic and marriage/divorce records.
A "paid' service will cost a visitor from $15-$300 and will certainly provide you with more complete and accurate data. These sites are a better choice for employment or legal situations.
Using a free background check in legal matters or the hiring of new employees is always a bad choice. There just isn't enough data contained in a free report to make a informed decision.
While a free background check may not provide as much information as a paid service; it is still very useful when conducting investigations on new people that you may meet. You can conduct your own searches here Free Online Background Check