The Infancy Defense
Infancy is a criminal defense, descended from British common law, that attempts to disprove liability for a crime by reason of the defendant's very young age. Under the assumption that minors are incapable of forming criminal intent in the same manner as adults, the common law infancy defense traditionally bars the prosecution of children under the age of seven for crimes and presumptively precludes the prosecution of children aged seven to fourteen years under the adult criminal law system. Contemporary statutes in United States criminal law, however, hold that children in the latter age group are eligible for prosecution through the juvenile justice system.
The infancy defense operates under the idea that children cannot be prosecuted as adults because they lack the emotional and cognitive maturity to understand the moral nature of their actions. At common law, children under the age of seven were held to be doli incapax, or irrebuttably incapable of forming criminal intent, while children between seven and fourteen were presumed such, though this presumption might be rebutted if very strong evidence was presented to show that the child held a moral understanding of his actions. The infancy defense at common law intended to strike a balance between the impropriety of punishing minors who are not responsible for their actions, and the dangers of categorically immunizing young people from prosecution, thus allowing them opportunity to commit serious crimes with impunity.
Statutory legislation in the United States has largely superceded the common law infancy defense through the establishment of a dual adult/juvenile justice system. Children under a certain age, usually between sixteen and eighteen depending on the state, are eligible for prosecution in a more lenient and rehabilitation-oriented juvenile justice system, while most states strictly bar the prosecution of very young children (usually under seven, though some states hold the age limit at ten.)
This pattern roughly mirrors original common law infancy defense. However, it does leave a question as to the place of the infancy defense in juvenile court proceedings. While there are a few exceptions, most courts in the United States have declared that the infancy defense has no place in cases of juvenile delinquency because this defense was intended to prevent minors from being prosecuted in adult courts, not juvenile courts. Furthermore, under a broad assumption that children today are more self-aware and self-determining than they were in the past, courts are increasingly finding evidence of real criminal intent in juvenile delinquents, often justifying the transfer of the young defendant to the jurisdiction of adult criminal courts.