How many years have they been in business. The longer a private investigator has been in business in a given area the better the chances are they are good at their job. They simply couldn't stay in business if they were satisfying their clients.
Do they come across a courteous professional? You want a private investigator that presents themselves in a professional manner both in person as well on the phone.
Are they open about what they will do to help solve your problem? Most good private investigators are willing to tell you the steps they will be taking on your behalf. A private detective who is too secretive should raise a red flag.
Are they willing to discuss their fees up front? Most people want to know what they are going to charge for any service and services provide by private detectives when serving legal papers or performing some other task should be no different.
If you live in Austraila and require the services of a professional private investigator then
why not contact Infoquest Investigation