There is no direct evidence...yet. The two are connected because Hale attempted to have Lefkow killed after she upheld a ruling that stated he could no longer use "World Church of the Creator" as the name of his white supremacist organization. Now that he's only a month away from sentencing, her husband and mother are dead. That is at least a moderately strong circumstantial link.
"There is no direct evidence...yet."
Tried and convicted case closed. LOL The guy is due for sentencing is exactly the reason he seems least likely to have anything to do with it. Still sounds like a botched robbery to me.