Judgement Day
Very rare3.5%All-the-thingsOptional
Phantom Liberty
Eliminate three bosses from the "Increased criminal activity" category.
There are three "Increased Criminal Activity" locations in Dogtown, which will be visible on your map. with a green triple-skull icon. Each one contains a boss - eliminate all three for this achievement. None are missable and all can be approached anytime.
The checklist indicates the rough map area in Dogtown for where to find each - but given the icons appear on your map they are not hard to locate, the checklist is just to keep track.