How to hire a private detective?

By hiring a private detective, always demand identification of the same.

Never pay any amount, without having made a contract to provide the service requested and that will be passed without a receipt.
Look out for advertisements in newspapers and the Internet, many of these ads are placed by individuals who pose as private detectives, who after receiving some money, end up doing absolutely nothing, and who had a problem to solve, stayed with a more.

If in doubt contact A.D.P.P.P.