Question: I want to file a contempt action to prove that someone is violating a Court Order. If I have someone take pictures to help prove this violation, does that person have to be a licensed private investigator?
Answer: Evidence of a violation of a court order can come from anyone with first-hand knowledge. If photos are being used for that purpose, the person taking them can introduce them at a hearing, and that person is not required to be a licensed private investigator.
However, if the person has any bias at all (such as being a friend or family member), then his/her credibility can be questioned and possibly compromised. When you use a private investigator, then his objectivity will not be questioned, as he is simply "doing his job."
Also, since a private investigator is essentially a professional witness, you will typically get better (i.e. more helpful) evidence than a non-professional would get. For instance, taking photographs in low light situations is difficult, and knowing what type of information the Court wants to see can make a big difference.
If you need more information, you can read the following articles that I've written about using private investigators in Family Court: