Calder v. Bull

On 8 August 1798, the Supreme Court ruled on the case. Two of the six justices did not weigh in on the dispute, while each of the other four issued his own opinion. All of them agreed on the outcome, however. Connecticut's legislation granting the Bulls a new hearing in probate court was found not to be an ex post facto law. The Court went even further in limiting the ex post facto provision to the realm of criminal law. The Calders' claim to Morrison's property was negated and the rights of possession were conferred upon the Bulls.

Justice Chase wrote the lead opinion in the case. In rendering his judgement, he relied upon the insight that, while all ex post facto laws are by definition retroactive, not all retroactive laws are ex post facto laws--and only the latter are unconstitutional. Chase limited his definition of an ex post facto law to four important types, all in the criminal rather than civil realm:

1st. Every law that makes an action, done before the passing of the law, and which was innocent when done, criminal; and punishes such action. 2nd. Every law that aggravates a crime, or makes it greater than it was, when committed. 3rd. Every law that changes the punishment, and inflicts a greater punishment, than the law annexed to the crime, when committed. 4th. Every law that alters the legal rules of evidence, and receives less, or different, testimony, than the law required at the time of the commission of the offence, in order to convict the offender.

Prohibitions against ex post facto laws, Chase concluded, were designed to protect citizens against unscrupulous prosecution, not to safeguard their private property rights. As Chase wrote: "The restraint against making any ex post facto laws was not considered, by the framers of the Constitution, as extending to prohibit the depriving a citizen even of a vested right to property."

To further buttress his argument, Chase pointed out constitutional language that expressly barred the passage of laws which impaired the obligations of private contracts. This, in his view, was an attempt by the framers to provide protections of property rights which were left unprotected by the ex post facto clause. If the framers had intended for the ex post facto clause to cover property disputes, these passages would have been redundant.

Chase's fellow justices largely agreed. Justice Paterson echoed his view that the ban on impairment of contracts suggested that the framers of the Constitution intended the prohibition of ex post facto laws to include "crimes, pains, and penalties, and no further." And Justice Iredell expressed the view that the purpose of the ex post facto clause did not extend to "civil cases, to cases that merely affect the private property of citizens."