The reason why all criminal records are not available in a nationwide search is that not every court system submits their criminal records to the databases that accumulate these types of records and make them available to the public. Because there are no central databases that are available to search criminal background records, the only way to ensure that you obtain all the available criminal records on a person would be to conduct a physical background search of the records of the more than 3,000 courts located across the nation. Companies that accumulate criminal records and sell them to the public have federal and state laws that restrict the type of information it is allowed to keep in its database.

The Fair Credit Reporting Act (FCRA) allows all convictions to appear in public records indefinitely. However, arrest records can only be kept for the last seven years from the date of entry. Depending on the state in which you reside, the criminal background records that are available to the public may be restricted even further. For example, California does not allow criminal convictions that are more than seven years old to be accessed through public records. Marijuana convictions for personal use which exceed two years old are not allowed to appear in databases in California. If an arrest does not result in a conviction, the information cannot be reported.

In some states, certain types of convictions can be expunged or sealed. Although the public does not have access to those records, law enforcement agencies may still be able to acquire the records. Some other factors that affect whether or not the criminal records are available in a nationwide search include criminal records recorded under a different name than the name you conduct the search under. Also, criminal records that are relatively new may not show up in a background check until the public records contained in the database are updated.