Why do the police always travel in threes? One does the reading,

Related:

• Q: Why do the police always travel in threes? A: One to do the reading,
  one to do the writing, and the other keeps an eye...
• Why does it take 3 Newfies to make chocolate chip cookies?
  One to stir the batter and the other two to peel the...
• May you travel the world over just one step ahead of
  the police...
• How many police -- does it take to change a light bulb?
  Three. One to change it and two to direct traffic (eh...
• How many liberals -- does it take to screw in a light bulb?
  Two-one to do it and the other to keep the first one's...
• How many NRA members -- does it take to screw in a light bulb?
  Two, one to do it and the other one to get his dick...
• Why do people spend years writing a novel when they
  can buy one for a few dollars...
• It is impossible to travel faster than the speed of light,
  and certainly not desirable, as one's hat keeps blowing...
• It is impossible to travel faster than light, and certainly not desirable,
  as one's hat keeps blowing off. -...