Comes from Crooks & Liars:

Florida Man Cites 'Bush Doctrine' After Pre-emptive Killing of Neighbors at Labor Day Cookout

And yes, that is exactly what it sounds like:

In their motion, Woodward’s attorneys claimed that the victims had called him names and threatened to "get him."

The motion referenced Enoch V. State, which suggests that an "imminent" threat can include something that is likely to occur at sometime in the future.

It may not take hold with this case, but the Bush Doctrine is the logical next step after Stand Your Ground: Get them before they get you. Imagine a future like Minority Report, only instead of Tom Cruise enforcing pre-crime with the help of the world's largest iPad and a hot tub full of psychics, it's just a bunch of average Americans with really strong hunches.