What to look for. What to expect. It would not be cost effective to hire a PI to accomplish tasks that you could do for yourself. Accomplish all you can on your own. This saves the PI time and you money.
Some investigators specialize in specific areas and others provide many types of services.
Pick a PI that specializes in your need or has a strong background in that area. Be skeptical of those who say they can do anything and advertise a multitude of services. What to look for. Also ensure that the PI is either insured or bonded. Ask for references.