BobChuck |
Vague question, but I would suggest the "Council of Thieves" adventure path by paizo.
It's not really a "mystery investigation"; I have never heard of any sort "mystery investigation" adventure module for D&D/pathfinder that was more than a one-shot.
But Council of Thieves has city politics and intrigue and acting, which is very much a part of the "mystery investigation" genre.