The problem is there isn't really much that can be plausibly be allowed as an investigative project in an otherwise all-vanilla game. There is no movements to track, nothing but alignments to discover, and a straight cop check would be broken.
In fact, all investigative either have intrinsic unreliability, or offer some sort of cumulative metric on more than one player. There
is
something which is basically a straight out Cop Check with some hoops in the game, but it's not in the investigative branch and I don't think they will ever try to build the necessary developments for it ;(