There are criminals in every profession, and contractors are no exception. Play it safe by getting a background check before you let any workmen into your home. Personal background checks are affordable (usually around $50), and they're only an Internet search away.
A good background check should tell you everything you need to know about your prospective contractor. It'll reveal any complaints that may have been filed against him and will look into his criminal history, sex offender status, credit rating, bankruptcy status and number of years in business. The report will also provide a civil records check (including lawsuits, tax liens and judgments), a scan for aliases, and a license and insurance check. While the background check can't guarantee that you're hiring an honest, reliable or competent contractor, it may very well provide the information you need to keep a criminal from entering your home.