Serious answer:
Check sex offender registry first as it's the easiest and will bring up the more heinous shit that you'll actually care about, complete with photo of offender, date of offense, etc.
For anything not sexually related, go to the website of the superior court of whatever county you know they have lived/operated in. There should be a case search tool somewhere on the page. It may be a pain to find.
Type name of the person you're looking up and give a broad range of dates if asked. You'll get a lot of red herrings this way so use common sense. If they went to troal for anything and didn’t have their case sealed or expunged, it will be there. Details may be sparse.