The U.S. Supreme Court case City of Canton, Ohio v. Harris et al., 1988 revolved around the issue of whether a municipality can be sued for constitutional violations caused by inadequate police training. The plaintiff, Geraldine Harris, was arrested and suffered injuries due to an alleged lack of proper medical attention while in custody; she claimed this constituted a violation of her rights under the Due Process Clause. The court held that municipalities could indeed be liable if it is proven that their failure to train employees amounts to "deliberate indifference" towards people's constitutional rights. However, proving such deliberate indifference requires showing more than just negligence or isolated incidents - there must be evidence suggesting an ongoing pattern or policy leading to such violations.

In the dissenting opinion for City of Canton, Ohio v. Harris et al., Justice O'Connor argued that a municipality could be held liable under Section 1983 not only when it fails to train its employees but also when it inadequately trains them, leading to constitutional violations. She disagreed with the majority's view that liability should only apply in cases where failure to train amounts to "deliberate indifference" towards citizens' rights. Instead, she proposed a standard based on "reckless or grossly negligent conduct." Furthermore, she contended that the plaintiff should not have been required to prove an ongoing pattern of police misconduct as evidence of inadequate training; instead, one instance demonstrating egregious disregard for constitutional rights would suffice. In her view, this approach better aligned with precedent and more effectively deterred future violations.