The United States Supreme Court placed "the serious and weighty responsibility . . . of determining whether there is an intelligent and competent waiver" directly upon the trial judge. In Von Moltke v. Gillies, 332 U.S. 708, 723-23, 92 L. Ed. 309, 68 S. Ct. 316 (1984), more specific guidelines were established: A judge must investigate as long and as thoroughly as the circumstances of the case before him demand. The fact that an accused may tell him that he is informed of his right to counsel and desires to waive this right does not automatically end the judge's responsibility . To be valid such waiver must be made with an apprehension of the nature of the charges, the statutory offenses included within them, the range of allowable punishments thereunder, possible defenses to the charges and circumstances in mitigation thereof, and all other facts essential to a broad understanding of the whole matter. A judge can make certain that an accused's professed waiver of counsel is understandingly and wisely made only from a penetrating and comprehensive examination of all the circumstances under which such a plea is tendered.