If you are not finding them in the shallows then maybe there are down deeper. A good friend of mine told me the other day on the phone that he was catching them in 26 ft deep water. The water column is mixed now and there is plenty of dissolved oxygen down deep now.
Find the food source and you will also find the crappie. And they may be moving from shallow to deep throughout the day. Bass will follow the shad into the shallows at night and then back out to the deep water as the sun rises in the mornings. Crappie also follow the food source. What is the forage at Brookville Lake. Gizzard Shad or something else?