(concurring in result).
I concur in the result and in the opinion except for the statement in division II, “We need not consider the efficacy of the rule eliminating the third element mentioned by McCormick.” Our long-standing rule, which is sound, is that the only additional evidence which is required, when a confession is admitted, is proof that the offense was committed. The statute so provides. Code, 1971, § 782.7. See State v. Leedom, 247 Iowa 911, 76 N.W.2d 773.