Private Investigators and Divorce
I once had a divorce where the husband was committing adultery. It was out, in the open, he didn't care who saw, and he wanted to be divorced. So much so, that he actually moved his girlfriend into the house. My client wanted pictures and evidence. She wanted to follow them around town and catch them holding hands. My question: Ma'am? For what? I'm willing to bet that he will sit on the witness stand and admit that he has committed adultery without a care in the world.
So, under what circumstances do you need this evidence, or to spend money trying to collect it? I would suggest that it's only when you need to bolster your grounds for divorce in order to actually convince your spouse that you will win if you have to prove grounds. Another scenario might be if you need evidence of moral conduct in a custody dispute - but remember, bad spouses don't automatically make bad parents and judges know that.
Just remember that real life isn't T.V., and private eyes aren't free, nor are they on your lawyers payroll. Always get the advice of your lawyer before you decide that you need to hire an outside source to assist in your divorce. They will be able to tell you whether it will help, hurt, or simply be a waste of your money