A criminal record is a record of a person's criminal history, generally used by potential employers, lenders etc. to assess his or her trustworthiness. The information included in a criminal record varies between countries and even between jurisdictions within a country. In most cases it lists all non-expunged criminal offenses and may also include traffic offenses such as speeding and drunk-driving. In some countries the record is limited to actual convictions (where the individual has pleaded guilty or been declared guilty by a qualified court) while in others it also includes arrests, charges dismissed, charges pending and even charges of which the individual has been acquitted. The latter policy is often argued to be a human rights violation since it works contrary to the presumption of innocence by exposing people to discrimination on the basis of unproven allegations.
Criminal records information is obtained from sources that include county and state criminal court records, federal fugitive files, state Department of Corrections (DOC) files, prison parole records and sex offender databases. Each level of search provides important information, as detailed below:
1. County Criminal Searches – The county criminal records search offers the most current detailed information, as it is being retrieved from the source. Note: If a crime was committed in county “A,” a search of the records in county “B” will not reveal the crime committed in county “A.”  Search the records in each county where the applicant is known to have lived or worked.
2. County Criminal Databases – Not all counties maintain their criminal records on a database. Arcane and fragmented record keeping systems still exist in many jurisdictions. Databases may not be current or accurate. If a name match is made, the actual records must still be retrieved for review from the county courthouse. In many jurisdictions, older records have been placed in storage. Therefore it is important that one’s search be thorough so as to not overlook any possible information of value.
3. Felonies & Misdemeanors – Most counties maintain separate records for felonies and misdemeanors. In some counties felony and misdemeanor records are maintained in a combined index. Felonies are the more serious crimes that carry a greater potential punishment, but misdemeanor convictions can include assaults, threats, weapons charges, and drug or alcohol related crimes. Check both categories and not assume that misdemeanors are simply related to traffic laws or noise ordinances.


Source1: http://www.answers.com/topic/criminal-record-1
Source2: http://howtoinvestigate.com/articles/criminal.htm
Source3: http://investigativeprofessionals.com/articles/index.htm