Anyone who's a whistleblower should compile key docs and put it in a "dead man's switch" service that releases your testimony/docs to multiple news agencies in the event of your untimely demise. The company you're whistle blowing against and their major shareholders should know this exists. Also, regularly post public video attesting to you current mental state.
What would that accomplish? Are you saying they won't kill you because then the documents would be released? So you would never release the documents if they never kill you? Or are you saying you'll do this so the documents are guaranteed to be released, even if you're killed? In that case, why not just publish them right now?
This is about leverage, and perhaps even bluff. It's never a binary situation, nor are there any guarantees.