when is an officer justified in using deadly force
Deadly force The United States Armed Forces defines deadly force as "force that a person uses causing, or that a person knows or should know would create a substantial risk of causing, death or serious bodily harm or injury".[2][1] In the United States, the use of deadly force by sworn law enforcement officers is lawful when the officer reasonably believes the subject poses a significant threat of serious bodily injury or death to themselves or others. The use of deadly force by law enforcement is also lawful when used to prevent the escape of a fleeing felon when the officer believes escape would pose a significant threat of serious bodily injury or death to members of the public. Common law allowed officers to use any force necessary to effect a felony arrest but this was narrowed in the Tennessee v. Garner ruling in 1985 when the U.S. Supreme Court said that "deadly force...may not be used unless necessary to prevent the escape and the officer has probable cause to believe that the suspect poses a significant threat of death or serious bodily harm to the officer or others." [1]
Castle doctrine According to the Criminal Code of Canada Sections 34 and 35,[48] (which were updated in 2012 with the passage of bill C-26) force, up to and including lethal force may be used in defence of one's life or "peaceably" possessed property or the defence of another's life or "peaceably" possessed property, and is not considered an offence so long as the person believes that force is being used against them in the case of self-defence, that someone is about to or has broken into or damaged property in the case of defence of property, that they are acting in defence of themselves, someone else or "peaceably" possessed property, and that the act is reasonable in the circumstances. The criminal code also lays out the factors in either case that will be used to determine what constitutes "reasonable given the circumstances". The changes made by the government were to clarify the laws involving self-defence and defence of property, and to help legal professionals to apply the law as believed to reflect the values Canadians hold to be acceptable.