A defendant who acts with an intent to kill individual A but accidentally kills individual B may still be found guilty of murder with intent to kill under the theory of transferred intent. This doctrine is also explained as "intent follows the bullet". The defendant may not even have to be aware the actual victim existed. Thus, the doctrine typically applies when a defendant fires a weapon at an intended victim and that bullet penetrates a nearby apartment, killing an actual victim.
Transferred intent will generally apply to any case in which the required state of mind is either intent or knowledge. However, if the crime is committed with recklessless or negligence, the application of the doctrine is not as certain. In these cases, the defense should argue that the doctrine either does not apply, or that a close connection between the intended and actual victim should be proven by the prosecution.
When the doctrine does not apply
The doctrine of transferred intent generally does not apply to attempt crimes.
The doctrine may not apply if the resulting harm is different in nature than the defendant intended. Thus, a defendant who intends to assault individual A but strikes B, killing that individual, may not be liable for the additional harm.
The doctrine may not apply if the actual victim was totally unforeseeable. The Model Penal Code Section 2.03(2)(b) states that the doctrine may not apply if the victim was "too remote or accidental in its occurrence to have a [just] bearing on the [defendant's] liability...."
Even if the doctrine applies, a defendant may be able to argue that the victim's injuries were not the proximate cause of the defendant's actions.
A defendant who is charged with a crime under a theory of transferred intent will still be able to raise the same defenses he would have if he had killed his intended victim. For example, if defendant was being attacked by a mugger and fired his pistol in self defense, he would still be able to raise self-defense as a defense against the killing of a third party.
Transferred intent and human fetuses
Suppose that a defendant is charged with firing a pistol at a pregnant woman. The intended victim survives, but her fetus is killed in the process. Does the doctrine of transferred intent apply? The answer may depend on the jurisdiction.
In People v. Taylor, 32 Cal. 4th 863 (2004), the defendant challenged the application of transferred intent to the death of a fetus. In Taylor, the defendant apparently shot his girlfriend in the head. An autopsy revealed she had been between 11 and 13 weeks pregnant. The prosecution proceeded on a theory of second degree implied malice murder as to the fetus. The California Court of Appeals reversed the conviction, concluding that "There is not an iota of evidence that that [defendant] knew his conduct endangered fetal life and acted with disregard of that fetal life. It is undisputed that the fetus was  to 13 weeks old; the pregnancy was not yet visible and [defendant] did not know was pregnant. Contrasting this with the case where a person fires through a window not knowing or caring if a person was inside the building, the court concluded that "[t]he undetectable early pregnancy [here] was too latent and remote a risk factor to bear on [defendant's] liability or the gravity of his offense." And "[T]he risk to unknown fetal life is latent and indeterminate, something the average person would not be aware of or consciously disregard." Taylor, at 867. The California Supreme Court reversed this decision, concluding that because the defendant acted with implied malice towards the mother, he had the requisite mens rea for the murder of the fetus.
In a dissenting opinion, Judge Kennard noted that foeticide was added by statute to the California criminal code after their decision in Keeler v. Superior Court, 2 Cal.3d 619 (1970). In Keeler the defendant was accused of accosting his obviously pregnant ex-wife and saying he was going to "stomp it out of you." He then kicked her in the stomach, killing the fetus. The prosecution attempted to charge him with murder of the fetus. However, the court concluded that a fetus was not a "human being" under the homicide statute. Kennard concludes from this case and the resulting legislative action demonstrated only intent to criminalize the knowing killing of a fetus. Therefore, he argued, the theory of transferred intent should not apply to accidental feticide.
State v. Merrill, 450 N.W.2d 318 (Minn. 1990) also approves the application of the doctrine of transferred intent to a fetus. In this case, the indictments charge the defendant with first and second degree murder of an unborn child under section 609.2661(1) and section 609.2662(1) of the Minnesota code for causing the death of an unborn child with "intent to effect the death of the unborn child or another, to-wit: Gail Stephanie Anderson, an adult female." The court concluded that "Ordinarily, the doctrine of transferred intent applies when the intent being transferred is for the same type of harm. If the harms are different, intent is not transferable. W. LaFave, supra, at 243. For example, an intent to murder cannot substitute for the intent required to convict for the malicious destruction of property that may have inadvertently been damaged during the murderous assault. In this case, defendant seems to be arguing that an intent to kill the mother is not transferable to the fetus because the harm to the mother and the harm to the fetus are not the same. We think, however, the harm is substantially similar. The possibility that a female homicide victim of childbearing age may be pregnant is a possibility that an assaulter may not safely exclude. We conclude, therefore, that the statutes provide the requisite fair warning."
At least one other court has concluded that the doctrine of transferred intent does not apply to fetuses. See People v. Shum, 512 N.E.2d 1183 (Ill. 1987) ["The exclusion of transferred-intent cases from the feticide statute was a rational decision by the legislature. An offender may be charged with feticide only where "he knew, or reasonably should have known under all of the circumstances," that his victim was pregnant. (Ill.Rev.Stat.1981, ch. 38, par. 9-1.1(a)(4).) In the case of an offender who intended to injure another, but instead harmed a pregnant woman, this element would be difficult, if not impossible, to establish"]. See also People v. Halmon, 225 587 N.E.2d 1182 (Ill.App. 1 Dist.,1992) the appellate division concluded that the doctrine of transferred intent did not apply to the state's now-abolished feticide statute.
The application of the doctrine appears to have been rejected in the UK. The House of Lords in AG's Reference (No. 3 of 1994) (1997) 3 AER 936 reversed the Court of Appeal decision (reported at (1996) 2 WLR 412), holding that the doctrine of transferred malice could not apply to convict an accused of murder in English law when the defendant had stabbed a pregnant woman in the face, back and abdomen. Some days after she was released from hospital in an apparently stable condition, she went into labour and gave birth to a premature child, who died four months later. The child had been wounded in the original attack but the more substantial cause of death was her prematurity.
Many of these cases seem to be grounded specifically in the language of the statute, so close attention should be paid to statutory basis of murder or transferred intent murder in your jurisdiction.