Section 627:5 Physical Force in Law Enforcement.
   I. A law enforcement officer is justified in using non-deadly force upon another person when and to the extent that he reasonably believes it necessary to effect an arrest or detention or to prevent the escape from custody of an arrested or detained person, unless he knows that the arrest or detention is illegal, or to defend himself or a third person from what he reasonably believes to be the imminent use of non-deadly force encountered while attempting to effect such an arrest or detention or while seeking to prevent such an escape.
   II. A law enforcement officer is justified in using deadly force only when he reasonably believes such force is necessary:
      (a) To defend himself or a third person from what he reasonably believes is the imminent use of deadly force; or
      (b) To effect an arrest or prevent the escape from custody of a person whom he reasonably believes:
         (1) Has committed or is committing a felony involving the use of force or violence, is using a deadly weapon in attempting to escape, or otherwise indicates that he is likely to seriously endanger human life or inflict serious bodily injury unless apprehended without delay; and
         (2) He had made reasonable efforts to advise the person that he is a law enforcement officer attempting to effect an arrest and has reasonable grounds to believe that the person is aware of these facts.
      (c) Nothing in this paragraph constitutes justification for conduct by a law enforcement officer amounting to an offense against innocent persons whom he is not seeking to arrest or retain in custody.
   III. A private person who has been directed by a law enforcement officer to assist him in effecting an arrest or preventing an escape from custody is justified in using:
      (a) Non-deadly force when and to the extent that he reasonably believes such to be necessary to carry out the officer's direction, unless he believes the arrest is illegal; or
      (b) Deadly force only when he reasonably believes such to be necessary to defend himself or a third person from what he reasonably believes to be the imminent use of deadly force, or when the law enforcement officer directs him to use deadly force and he believes such officer himself is authorized to use deadly force under the circumstances.
   IV. A private person acting on his own is justified in using non-deadly force upon another when and to the extent that he reasonably believes it necessary to arrest or prevent the escape from custody of such other whom he reasonably believes to have committed a felony and who in fact has committed that felony: but he is justified in using deadly force for such purpose only when he reasonably believes it necessary to defend himself or a third person from what he reasonably believes to be the imminent use of deadly force.
   V. A guard or law enforcement officer in a facility where persons are confined pursuant to an order of the court or as a result of an arrest is justified in using deadly force when he reasonably believes such force is necessary to prevent the escape of any person who is charged with, or convicted of, a felony, or who is committing the felony of escape from official custody as defined in RSA 642:6. The use of non-deadly force by such guards and officers is justified when and to the extent the person effecting the arrest believes it reasonably necessary to prevent any other escape from the facility.
   VI. A reasonable belief that another has committed an offense means such belief in facts or circumstances which, if true, would in law constitute an offense by such person. If the facts and circumstances reasonably believed would not constitute an offense, an erroneous though reasonable belief that the law is otherwise does not make justifiable the use of force to make an arrest or prevent an escape.
   VII. Use of force that is not justifiable under this section in effecting an arrest does not render illegal an arrest that is otherwise legal and the use of such unjustifiable force does not render inadmissible anything seized incident to a legal arrest.
   VIII. Deadly force shall be deemed reasonably necessary under this section whenever the arresting law enforcement officer reasonably believes that the arrest is lawful and there is apparently no other possible means of effecting the arrest.
Source. 1971, 518:1. 1981, 373:1-3, eff. Aug. 22, 1981.