Nightstick

The Nightstick (or Tonfa) is a new close-combat weapon introduced in Left 4 Dead 2.

The Nightstick, like every other melee weapon, is not really meant to be used against Special Infected, because using it on a Boomer would cover you in bile, and killing a Spitter would leave you right in the middle of the goo. It would also take time to get to a Charger, Jockey, Hunter or Smoker. Against a Tank or Witch it would do little to no damage.

This weapon is dropped by Riot Infected when killed, assuming they are carrying it around their waist.

Trivia

 * Although the Survivors call it a nightstick, the proper name for this weapon is a Tonfa.
 * In the original Left 4 Dead, many Infected police officers have nightsticks hanging from their belts, though they can not be picked up upon their death.
 * The weapon is or strongly resembles a Monadnock PR-24 police baton, commonly associated with law enforcement officers. It can be distinguished from a true tonfa in that it is not made of wood and is used alone rather than in a pair.
 * Having the Nightstick as an instant kill weapon is strange, since in real life, they are designed specifically not to kill.
 * The Nightstick appears to hit slightly faster than all other melee weapons.