The Defendant's Confession. The only basis of challenge to the competency of defendant's confession is that he was under arrest, being held without warrant, and was in custody at the time it was given. These circumstances, taken singly or all together, unless they amounted to coercion, were not sufficient in and of themselves to render a confession, otherwise voluntary, involuntary as a matter of law and incompetent as evidence. S. v. Stefanoff, 206 N.C. 443, 174 S.E. 411; S. v. Gray, 192 N.C. 594, 135 S.E. 535; S. v. Thompson, 224 N.C. 661, 32 S.E.2d 24; S. v. Litteral, 227 N.C. 527, 43 S.E.2d 84; S. v. Speller, 230 N.C. 345, 53 S.E.2d 294; S. v. Brown, 231 N.C. 152, 56 S.E.2d 441. After a preliminary investigation, pursuant to the procedure outlined in S. v. Whitener, 191 N.C. 659, 132 S.E. 603, the trial court ruled the confession to be voluntary, and permitted the solicitor to offer it in evidence against the prisoner.