Johnson v. Zerbst
United States Supreme Court
304 U.S. 458 (1938)
Johnson (plaintiff) was tried for counterfeiting after telling the judge he was willing to proceed without a lawyer; he was convicted and imprisoned, where he was denied legal help and missed his appeal deadline. He petitioned for habeas corpus against the prison warden, Zerbst (defendant), arguing his trial without counsel violated the Sixth Amendment, but the district court never determined whether he'd validly waived counsel, dismissing his petition instead on the ground that his missed appeal deadline (whether from ignorance or negligence) didn't confer habeas jurisdiction; the court of appeals affirmed.
Whether the Sixth Amendment guarantees a criminal defendant the right to a lawyer's assistance unless the defendant knowingly and intelligently waives that right.