You may think, why should I pay for that service? I can do that myself, or if you are in business why invest the money?
Would you be investigating a person, or persons with whom you already had a relationship and still have some attachment, therefore making you recognisable or show you may have a vested interest in manoeuvring what you uncovered, to your advantage.
Would you know what methods to use in order that any evidence would be collected, processed and delivered in a legal manner that could back your case when necessary?
Investigators have access to a whole network of experienced specialists, increasing efficiency.
Of high importance is the fact they can remain impartial and anonymous thereby increasing the prospects of a successful resolution.