I know everything can pretty much show, but not everything is relevant in terms of hiring a good employee. What types of things are employers usually concerned with?
Any felony convictions.
Drug charges.
Sexual assault
assault in battery / aggravated assault
Domestic violence
Identity theft
theft
etc...
Criminal record.
Credit rating.
References.
Personal injury lawsuits.
Many employers are now checking social websites such as Facebook. People who have posted pictures of themselves doing stupid or illegal things are likely to regret it.
Just about anything really.
The biggest ones would be workplace theft or workplace violence.
Another really important thing they check for is anything that comes up in the background investigation that you did not disclose beforehand. The moment we see that we wonder: "What else is he/she not telling us that we haven't caught?"
Criminal record, bad credit rating, frequently changing jobs, moving a lot, and drug use.