I would have suggested Crawford Investigative Services, but I was just informed last week by one of their investigators that MJM just bought out Crawford. I understand that they are currently in a state of flux at the moment with the logisitcs of the takeover and so I don't know if they are hiring or not.
Another source may be to join Unified Investigative Services if they are hiring. You can find their information from the following website: [
www.UIS-USA.COM]
I hope this helps. Good luck.
Chris