In the case of Keith Jacobson v. United States, 1991, the Supreme Court ruled in favor of Jacobson by a 5-4 decision. The Nebraska farmer was convicted under federal law for receiving child pornography through mail after being targeted and entrapped by undercover postal inspectors over two years. The court found that government agents had implanted a criminal design into an innocent person's mind and then induced its commission so they could prosecute it. They argued that if not for the extensive efforts to stimulate his interest in illegal materials, there would have been no crime committed as he showed no predisposition towards such behavior prior to their intervention. Therefore, this constituted entrapment on part of the government officials which is prohibited under U.S law.

In the dissenting opinion for Keith Jacobson v. United States, Justice O'Connor argued that the majority's decision failed to properly apply the legal standard of "predisposition" in entrapment cases. She contended that Jacobson was not predisposed to commit a crime before government agents intervened and thus should have been protected by entrapment laws. The justice believed that it was inappropriate for law enforcement agencies to generate new crimes merely as a means of prosecuting individuals who are otherwise innocent, arguing this approach undermines citizens' trust in their government and violates principles of fairness and due process. Furthermore, she criticized the majority's reliance on evidence from years prior to establish predisposition when there were no illegal materials involved at that time.