In the past, my investigator (from S.O. or P.D.) has been able to testify about grooming by child predators. I'm now in such a rural jurisdiction that my "investigator" is not familiar with this behavior nor do I want him on the stand any longer than necessary. Who, if anyone, do you all use to talk about such behavior?

You may want to try your local Children's Advocacy Center. They usually have someone well versed in the subject. Absent that, there are a number of experts to try (give me a shout and I will try to come up with some names for you). The FBI also has some good experts, and the feds may be able to lend you some help.

Does your probation department have a psychologist/counselor that they use for sexual offenders on probation? Juvenile probation department? How about your local CPS office--who do they have (and ask your local Regional Attorney for CPS if you do not normally handle CPS cases).