In McNeil v. Director, Patuxent Institution (1971), the U.S. Supreme Court ruled that a Maryland law allowing for indeterminate sentencing and treatment of "defective delinquents" was not unconstitutional on its face but could be applied unconstitutionally if it resulted in longer confinement than the maximum sentence allowable for an offense. The case involved Robert Laverne McNeil who had been committed to Patuxent Institution under this law after being convicted of robbery with a deadly weapon. He argued that his commitment violated his constitutional rights because he was confined beyond the statutory maximum for his crime without proof of mental illness or dangerousness beyond a reasonable doubt, as required by due process clause of Fourteenth Amendment. However, the court held that while indefinite detention based solely on criminal propensity would violate due process, such detention is permissible when there's clear evidence showing both mental abnormality and potential danger to public safety.

In the dissenting opinion for McNeil v. Director, Patuxent Institution, Justice William O. Douglas argued that the majority's decision was a violation of due process rights under the Fourteenth Amendment. He contended that Maryland's Defective Delinquent Act, which allowed for indefinite detention based on an individual’s potential future dangerousness, was unconstitutional as it did not provide adequate procedural safeguards to protect individuals from erroneous commitment decisions. Douglas also criticized the use of psychiatric predictions in determining an individual's potential danger to society and emphasized their inherent unreliability and subjectivity. Furthermore, he expressed concern over how such laws could be used to suppress political dissent by labeling dissidents as mentally ill or potentially dangerous.