In Davidson v. Cannon et al., 1985, the US Supreme Court ruled that a prisoner's due process rights were not violated when prison officials negligently failed to protect him from another inmate's attack. The plaintiff, an inmate named Davidson, had informed prison authorities about threats made against his life by another prisoner but was later attacked and injured by this same individual. He sued the officials for failing to take adequate measures to ensure his safety despite being aware of the threat. However, in a unanimous decision led by Justice William Rehnquist, the court held that negligence did not amount to deliberate indifference required under Due Process Clause of Fourteenth Amendment and therefore did not constitute a constitutional violation.

In the dissenting opinion for Davidson v. Cannon, Justice Brennan disagreed with the majority's view that negligence by state officials did not constitute a violation of due process rights under the Fourteenth Amendment. He argued that when an individual is in custody and entirely dependent on prison officials for protection, those officials have a constitutional duty to protect him from violence at the hands of other prisoners. According to Brennan, this obligation arises from both substantive and procedural aspects of due process because it involves safeguarding personal security - one of life’s basic necessities which cannot be denied without violating fundamental fairness standards. The failure by prison officers to act upon information about threats against Davidson was more than mere negligence; it amounted to deliberate indifference towards his welfare thus constituting a breach of their constitutional duty.