I used to work for one. I did a lot of the reports in the office, not the actual investigations, and I put all the video's together.
It depends really on what you WANT to know. Financial? Internet/phone/computer history stuff? Where he goes when he's not with you??? I mean there is so much that is offered, I'm not sure how to answer.
I would NOT suggest that you just go searching through the yellow pages though. Check who they are associated with, like World Association of Detectives for instance is good.
Hope this helps.BS - Me
DDay 1 - Jul 11
DDay 2 - Jul 12
R Dec 12
Former 80s Icon wishful thinking