Get as much identifying information as you can on the person you want to research. Make sure you have the correct spelling of his name, middle name, aliases, a date and place of birth and a social security number.
Ask about previous convictions. Get the county where the case was filed, case number, filing and conviction dates, charges and the name the person was using, if possible. This also helps you determine your prospective employee's integrity if you find a record she didn't report on her application.
Ask about the employee's address history for the past 7 years. Some courts keep records for longer, but a 7-year search is the standard. You may have to pay additional fees if you want to go back further.
Tap into court databases offered free over the Internet (see link in Resources). Check the counties where your prospective employee has lived. Be sure to search under all aliases you know of.
Print any information you get from your searches. These records will likely include basic case information, so you'll need to send a researcher to the courthouse to find out the details.
Look up the city of the federal district court that covers the counties you need to search. You'll need to send researchers to the federal courthouse in that city to get cases where the defendant violated a federal law or committed a crime across state lines.
Search the Public Record Retriever Network Membership List for someone to do criminal records research (see Resources). Find someone in each county where your prospective employee has lived for the past 7 years as well as in the counties of the federal district courts.