In Palko v. Connecticut (1937), the Supreme Court had to decide whether "due process of law" means states must obey the Double Jeopardy Clause of the Fifth Amendment
Explanation:
The observation of the Supreme Court is that the convict cannot be punished two times for the same offense. It is simple and very clear that the convict cannot be punished under the fourth and fifth amendments for same offense.
In this particular case, the prosecution has charged Frank Palko for first-degree murder and the court has given a decree as life imprisonment. But the actual nature crime amounts to second-degree murder.
So, the state of Connecticut appealed against this judgment and it has been proved that offense made by Frank Palko amounts to second-degree murder and the death penalty is awarded to convict. The Supreme Court's main decision in Palko vs Connecticut was Palko was the victim of unconstitutional double jeopardy.