overkill

Short definition from Wiktionary

Noun

1. 1
   A destructive capacity that exceeds that needed to destroy an enemy; especially with nuclear weapons.
2. 2
   Destruction beyond what is necessary to kill, especially in murder.
3. 3
   An unnecessary excess of whatever is needed to achieve a goal.
4. 4
   An unnecessary excess of disposal because of too high criteria of inspection.

Verb

1. 1
   To destroy something with more (nuclear) force than is required.
2. 2
   To dispose of too many items because of too-high criteria of inspection.
3. 3
   To do something excessive to achieve a goal.