Why not a federal investigation of clergy abuse?

There have been calls for more state-level inquiries, but abuse has occurred nationwide, and the church has failed to act as needed. The St. Paul Cathedral. Attorney Jeff Anderson is calling for a grand-jury investigation into clergy sex abuse in Minnesota. One conducted in Pennsylvania drew widespread attention. Following what may be the most comprehensive examination to date of clergy sex abuse across a single state, in Pennsylvania, attorney Jeff Anderson is now calling for a grand-jury investigation across Minnesota into clergy sex abuse. Such investigations have been announced in Missouri and Illinois. One is also being called for in New York.

http://www.startribune.com/why-not-a-federal-investigation-of-clergy-abuse/492034851/