In the criminal law, the duty to retreat is a specific component which sometimes appears in the defence of self-defence, and which must be addressed if the defendant is to prove that his or her conduct was justified. In those jurisdictions where the requirement exists, the burden of proof is on the defence to show that the defendant was acting reasonably. This is often taken to mean that the defendant had first avoided conflict and secondly, had taken reasonable steps to retreat and so demonstrated an intention not to fight before eventually using force.
In English law
the focus of the test is whether the defendant is acting reasonably
in the particular situation. There is no specific requirement that a person must retreat in anticipation of an attack. Although some withdrawal would be useful evidence to prove that the defendant did not want to fight, not every defendant is able to escape. In R v Bird
(1985) 1 WLR 816 the defendant was physically attacked, and reacted instinctively and immediately without having the opportunity to retreat. Had there been a delay in the response, the reaction might have appeared more revenge than self-defence. It might be different if the defendant sees an enemy approaching and decides to stand his ground. The answer may depend on where the threat is recognised. In a public place, where there are many other people present, a judgment must be made on whether an attack is imminent. As a matter of policy, no-one should be forced out of the streets because of fear, but prudence might dictate a different answer at night when the streets are empty.
As to carrying weapons in anticipation of an attack, Evans v Hughes
(1972) 3 A ER 412 held that for a defendant to justify his possession of a metal bar on a public highway, he had to show that there was an imminent particular threat affecting the particular circumstances in which the weapon was carried. Similarly, in Taylor v Mucklow
(1973) CLR 750 a building owner was held to be using an unreasonable degree of force in carrying a loaded airgun against a builder who was demolishing a new extension because his bills were unpaid. More dramatically, in AG's Reference (No 2 of 1983)
(1984) 1 AER 988 Lane CJ. held that a defendant who manufactured ten petrol bombs to defend his shop during the Toxteth riots
could set up the defence of showing that he possessed an explosive substance "for a lawful purpose" if he could establish that he was acting in self-defence to protect himself or his family or property against an imminent and apprehended attack by means which he believed to be no more than reasonably necessary to meet the attack.