In the United States v. Shearer case of 1984, the Supreme Court ruled that a military serviceman's mother could not sue the U.S. government for her son's off-duty murder by another serviceman. The victim’s mother argued that the Army was negligent in its supervision of Andrew Heard, who had previously been convicted of manslaughter and showed signs of violent behavior but was still allowed to serve overseas where he murdered Private Vernon Shearer while off duty. The court held that under Feres Doctrine - which prevents suits against the federal government by members of armed forces for injuries arising out from or during their service - Mrs. Shearer’s claim was barred as it essentially questioned military discipline and decision-making, matters constitutionally vested with Congress and Executive Branch.

In the dissenting opinion for United States v. Shearer, Justice Brennan disagreed with the majority's decision to uphold immunity of military personnel from lawsuits arising out of their official duties. He argued that this case was not about a soldier performing his duty but rather involved an off-duty serviceman committing murder in civilian life. He believed that such actions were outside the scope of employment and thus should be subject to civil liability under state law. Furthermore, he criticized the majority’s reliance on Feres Doctrine - which grants immunity to military personnel from tort claims for injuries related to service - stating it had been misapplied and extended beyond its original intent. In conclusion, Justice Brennan contended that by denying Mrs.Shearer her day in court against her son's murderer, they denied justice itself.