I've been wondering why everyone has already determined that this Hale character is involved. Now, it sure looks like it, but come on-- like you said, her husband was a criminal defense attorney (in CHICAGO). Surely he was dealing with very unsavory characters too. Then there is always simply a random act of violence that has nothing to do with their careers.
I feel horrible for this women. I knew a DA once whose entire family was under a death threat for a few years from gang members. He had 3 kids under 5 (everyone's okay, but imagine the worrying).
That's my thinking too.
If the police only go on that basis, they may end up missing important clues that point elsewhere.
Tragic to be sure, but we shouldn't jump to conclusions and just blame the obvious nut cases. It could be random violence or a break in gone bad.