The biggest clue we've been given so far hides in plain sight:
"There is nothing that has brought us to any conclusion that somebody did this to Kathleen," said Lake County Sheriff's Office spokesperson Sgt. Christopher Covelli. "We don't have any evidence somebody caused this to happen to Kathleen."
Let's parse this.
First sentence states almost directly, Kathleen Ryankilled herself. The door's left open a crack, just in case nefarious gang-bangers or paid hit men or crazed acquaintances or vengeful family members or Lone Nut Jobs enter the picture. But LE does not make this statement unless it's very sure and by using the word "us," suggests that great team effort has been put in. Also, to make this statement, LE must have information they are withholding from the public, things which might cause someone to suicide: bad relationship, on-job stress, return of a disease. You can bet they've talked to her husband, her bosses, her doctors. And they found out something.
Second sentence - "we" goes with first sentence's "us" -- LE has put in due diligence plus overtime. There's just not any evidence on the other side of the ledger: no one killed her but herself. The only "somebody who caused this to happen" is the dead woman herself.
Again, I was bowled over by spokesperson Sgt. Covelli's statement. It almost can't get more clear. You just don't say this in an official capacity unless you're pretty damned sure it won't come back to haunt you.