How did Malloy v. Hogan apply the Fifth Amendment protection against self-incrimination to state governments?

In Malloy v. Hogan (1964), the Supreme Court established that the Fifth Amendment’s protection against self-incrimination applies to state governments as well as the federal government.1

Prior to this decision, the Fifth Amendment’s protections were not automatically binding on the states. The Court achieved this extension through the process of "selective incorporation," which uses the due process clause of the Fourteenth Amendment to apply specific rights guaranteed in the Bill of Rights to state-level legal proceedings. By ruling that the privilege against self-incrimination is a fundamental right, the Court ensured that state defendants are protected from being compelled to testify against themselves, effectively holding both state and federal levels of government to the same constitutional standard. This landmark ruling laid the essential groundwork for the Court's subsequent decision in Miranda v. Arizona (1966).21