While playing the game(you lost btw) over the last few months, I've noticed a couple things. One I'm more than sure works, I've seen it. The other I'm not too sure but it seems to be true sometimes.
So here is the theory:
When a body is located, and the person locking said body has not said a specific person killed, look closely at the chat. The imposter will almost always be one of the first three people to say "where".
The second theory, and I think people have caught on to this one, is the first person to suggest skipping is sometimes the imposter as well. This one I'm not too sure on, because a lot of the games I've played lately aren't getting skipped as much, and or people don't mention skipping.
Try it out, and let me know if the first theory works in your favor. It may stop happening as much in the near future, but it happens a LOT in the games I've been playing.