What is the test for reversal of a finding that a statement was admitted against appellant in violation of the Miranda rights?

Appellant also argued that reversal was required because of the admission of a statement taken from appellant in violation of Miranda v. Arizona, 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694 (1966). We agree.

Appellant was arrested and advised of his rights under Miranda. He refused to make a statement. Three hours later he was again interviewed, while still in custody and handcuffed. One of the two agents present knew of appellant's prior refusals to give a statement. He was again advised of his Miranda rights. The interviewing agent urged appellant to cooperate and told him his cooperation would be called to the attention of the United States Attorney. (A permissible tactic, 'standing alone,' at least when employed prior to an initial refusal. United States v. Glasgow, 451 F.2d 557, 558 (9th Cir. 1971).) The interrogating agent then confronted appellant with a description of federal prison. The interrogating agent's version was that appellant was told that prison was a 'dark place,' where they 'pump(ed) air' to the prisoners. Appellant's version was that he was told that unless he cooperated he would be put in a concrete room and air would be pumped to him through a pipe. The interrogation then proceeded, and appellant gave the statement admitted against him.