Metropolitan Police Commissioner v Caldwell  AC 341 is an English criminal law case that established the Caldwell test of recklessness.
Caldwell had been working at a hotel and had a grudge against his employer. One night after consuming a large quantity of alcohol he went to the hotel and started a fire which was discovered and distinguished early and no people were harmed. He was convicted of aggravated criminal damage under s1(2) Criminal Damage Act 1971 and appealed in relation to the required level of recklessness, arguing that he had given no thought as to the possible endangerment of life due to his intoxicated state.
The House of Lords upheld his conviction and formulated what has become known as Caldwell recklessness:
A person is reckless where he carries out an act which creates an obvious risk for the destruction or damage of property and he has, at that time, not contemplated the possibility of the risk or has recognised that some risk exists, but has nevertheless continued with his course of action.
It should be noted that the Caldwell test of recklessness has been overruled in R v G and another  UKHL 50.