We need to find a way to deal with authority in nearly every mystery or thriller we write. If the protagonist is not actually the policeman, FBI agent, or other authority figure on the case, then he has two choices when the conflict ensues: involve the authorities, or have a damn good reason not to. Because if he simply ignores the fact that law enforcement exists for the purpose of solving crimes, the reader won't buy it.
Here are a few techniques for neutralizing authority - or better yet, using them to up the stakes.
1) Make the protagonist a suspect. A technique that instantly adds a new subplot, this is also a great way to incorporate Option Number Two.
2) Corrupt the police department. No smart protagonist turns to an authority figure who is stupid or incompetent, and especially not to one who has his own agenda.
3) Create a conflict that only the protagonist has the expertise to solve. The Loch, by Steve Alten, is a great example of this. Who better to scientifically determine the existence of the Loch Ness Monster than a marine biologist. Which leads us to...
4) Create a villain who is not human, or a conflict that is not a crime. Cujo. The Birds. Anything with a vampire in it. In today's world of obsession with the supernatural, the sky is the limit.
5) Put the action in the middle of nowhere. Start with a shipwreck, or an avalanche, or anything that isolates the characters. This can also create a ticking time bomb: the ship is sinking. They are running out of food.
What are some of your techniques for neutralizing the authority figure?