Other than your typical computer searches, you could hire a P.I. Many will ask why you want info on a person. Acceptable reasons would include to find a long lost relative or friend, get an ex to pay child support/alimony, find out if a spouse is cheating, etc.
If the person lacks a criminal record, you'll just get a list of former addresses and phone numbers, and the high school they graduated from.
It is expensive to hire a P.I. If you believe that a person is currently engaging in illegal acts, it might be worth it to pay someone to follow and photograph them.
