Actus reus, abbreviation of the introductory words of the Latin expression actus non facit reum nisi mens sit rea (« an act does not make a person guilty unless his mind is also guilty »), is an element of a crime that a prosecutor must prove in order to establish criminal responsibility. In particular, the prosecutor must prove that the defendant`s actus reus caused the harmful result in question. To do this, the prosecutor must prove not only that the act was the « actual cause » of the harm (i.e., the « factual cause » or the « without » cause), but also that the act was the « direct cause » of the harm (i.e., the « legal cause »). To be convicted as the principal perpetrator of aiding and abetting the commission of a crime, a jury must establish beyond a doubt that the accused knowingly and intentionally aided and abetted the principal or principals in all essential elements of the crime. United States v. Bancalari, 110 F.3d 1425, 1429 (9th Cir. 1997). The government must prove that the defendant is associated with the criminal enterprise, intentionally participated in the criminal activity, and attempted to make the business successful through his or her actions. United States v. Landerman, 109 F.3d 1053, 1068 n.22 (5th Cir. 1997); United States v. Griffin, 84 F.3d 912, 928 (7th Cir.), cert.
denied, __ U.S. __, 117 pp. 495, 136 L.Ed.2d 387 (1996); Pipola, 83 F.3d to 562; United States v. Lucas, 67 F.3d 956 (D.C. Cir. 1995); Spinney, 65 F.3d to 238; United States v. Williamson, 53 F.3d 1500, 1515 (10th Cir. 1995); United States v. Roach, 28 F.3d 729, 736-37 (8th Cir. 1991); United States v.
Ritter, 989 F.2d 318, 322 (9th Cir. 1993). A defendant joins a criminal enterprise if they share the client`s criminal intent, and the defendant engages in criminal activity if they have acted positively to support the business. Landerman, 109 F.3d to 1068 n.22. The level of participation can be relatively low. Leos-Quijada, 107 F.3d to 794. Nor is it necessary for much evidence to satisfy the element of facilitation once the defendant has knowledge of the unlawful purpose. United States v. Bennett, 75 F.3d 40, 45 (1st cir.
1996). There are two tests that courts can apply where there are more than one reasonable grounds. The first is the essential factor test, according to which a defendant is criminally liable if his or her actions are considered to be an essential factor causing harm to the alleged victim. This criterion is not widely used as it can be arbitrary and subjective. The best test is a modified form of the « without » test, which reads as follows: « Without the voluntary action of the accused, the damage would not have occurred only at that time, but in this way. » Even this revised test is not ideal. For example, it is not clear how this criterion is used when two non-lethal acts are combined to cause the death of a victim. In tort, it must be established that the tortious conduct of the defendant caused or contributed substantially to the damage suffered by the plaintiff before the plaintiff could be held liable for that damage. In determining actual causation, courts apply the same « but for » test used in criminal cases: « Would the plaintiff`s injury have occurred but for the defendant`s tortious conduct (Barnett v Chelsea and Kensington Hospital Management Committee [1969] 1 QB 428)? However, this assessment is insufficient for cases of simultaneous or cumulative causes where the actions of two or more perpetrators are sufficient to cause the damage.
If there is more than one possible cause, several tests can be applied. For example, did the defendant`s negligence significantly increase the risk of harm (Mc Ghee v National Coal Board [1973] 1 WLR 1)? Was the defendant`s breach of duty also a significant cause of the damage? One in five grounds is not sufficient to establish liability (Wilsher/Essex Area Health Authority, 1988, AC 1074). For causation to be established on a balance of probabilities, there must be at least a 51% probability that the defendant`s actions caused the damage (Hotson v East Berkshire Health Authority [1987] AC 750). United States v. DePace, 120 F.3d 233 (11th Cir. 1997); United States v. Chávez, 119 F.3d 342 (5th Cir. 1997); United States v. Powell, 113 F.3d 464 (3d cir.
1997); United States v. Sayetsitty, 107 F.3d 1405 (9th Cir. 1997); United States v. Leos-Quijada, 107 F.3d 786 (10th Cir. 1997); United States v. Estates, 105 F.3d 1565 (8th Cir.), cert. denied (6 October 1997) (No. 96-9541); United States v. Pipola, 83 F.3d 556 (2d Cir.), cert. denied, __ U.S. __, 117 pp.
183, 136 L.Ed.2d 122 (1996); United States v. Kinn, 83 F.3d 83 (4th Cir. 1996); United States v. Lucas, 67 F.3d 956, 959 (D.C. Cir. 1995); United States v. Spinney, 65 F.3d 231 (1. cir. 1995); United States v. Spears, 49 F.3d 1136 (6th Cir. 1995).
1) Actual causation: It must be proved that the event would not have occurred « without » the defendant`s action. The action must be a cause sine qua non (« cause without which ») of the event. A test sometimes called a « but for » test. The elements necessary to convict under the theory of complicity are 1. that the accused had a concrete intention to facilitate the commission of one crime by another; (2) Legal causation: The defendant`s action must be an operational and substantial cause of consequence. His act does not necessarily have to be the sole cause, but must make a substantial and non-trivial (de minimis non curat lex) contribution to the result. For example, if a doctor takes a blood sample from a patient who has been stabbed and dies, the blood sample will weaken the patient, but the physician`s role in the patient`s death is minimal and causally insignificant. Whatever criteria of causation exist or prevail in a particular case, a prosecutor must establish beyond doubt all the elements of a crime. This standard is at least legal certainty. It is difficult to determine causality when two people perform different actions at different times and each of their actions could have caused the damage at the time of the damage.
The two actions of the two different persons simultaneously constitute sufficient causes in the context of the « but for » criterion. Since there are two different persons who could have « caused » the harm after the « but for » test, but only one of the two persons actually caused the damage, the « but for » test cannot establish causation. The relationship between an action and the consequences it entails. This is one of the elements that must be proven before a defendant can be convicted of a crime when the effect of the act falls within the definition of the crime (e.g., murder). Irrespective of the other causes which may have led to the emergence of the actus reus, it must be shown that the defendant`s conduct contributed significantly to the actus reus. In R v White [1910] 2 KB 124, White gave poison to his deceased mother. However, medical evidence proved that the mother had died of a heart attack and that the poison was in no way related to death. The defendant`s conduct therefore did not contribute in any way to the resulting death. Causation is a question of both (1) facts and (2) law, and in both cases it is a question for the jury to decide:(1) Causation of facts: It must be proved that the event would not have occurred « without » the act of the accused.
The action must be a cause sine qua non (« cause without which ») of the event. a test sometimes called the « but for » test.2) Legal cause: The defendant`s action must be a concrete and substantial cause of the result. His act does not necessarily have to be the sole cause, but must make a substantial and non-trivial (de minimis non curat lex) contribution to the result. For example, if a doctor takes a blood sample from a patient who has been stabbed and dies, the blood sample will weaken the patient, but the physician`s role in the patient`s death is minimal and causally insignificant. Sometimes a new act or event (novus actus (or nova causa) intervenes) can break the legal chain of causality and relieve the defendant of liability.