Misdemeanor and Felony
This is the most basic type of criminal background checks. However, you need to inquire as to the level at which this is being performed. Is it specific to a certain county, or does it cover state-wide or even nation-wide records? County records may not have information regarding felonies and misdemeanors committed in other areas, even in the neighboring county. State and national records, as well as international records if the applicant ever lived overseas, are just as important.
Federal
A crime committed on federal property or against a federal entity is tried in a federal court. Therefore, these records will not be found during a traditional criminal background check unless you specifically request it.
Wants/Warrants
A person may not have any outstanding issues on a criminal report, but it is important to know whether there are any outstanding charges or warrants for that person for which they have not officially been charged.
Homeland Security
While the chances are very small, it may be wise to include a criminal check with Homeland Security.
Sex Offenders
Checking the sex offenders list is something that you may want to do depending on the type of work in which you are involved. In many areas, the sex offenders list is public information that can be searched by anyone.