"Determining the competency of a witness to testify is a matter which rests in the sound discretion of the trial court. State v. Phillips, 328 N.C. 1, 17, 399 S.E.2d 293, 301, cert. denied, 501 U.S. 1208, 115 L. Ed. 2d 977 (1991).
"To test the competency of a witness, the trial judge must assess the capacity of the proposed witness to understand and to relate under oath the facts which will assist the jury in determining the truth with respect to the ultimate facts. State v. Liles, 324 N.C. 529, 533, 379 S.E.2d 821, 823 (1989).
"'Conflicts in the statements by a witness affect the credibility of the witness, but not the competency of the testimony.' State v. Cooke, 278 N.C. 288, 291, 179 S.E.2d 365, 368 (1971) (quoting 7 Strong's N.C. Index 2d, Witnesses § 2).
"There is no age below which one is incompetent as a matter of law to testify. State v. Eason, 328 N.C. 409, 426, 402 S.E.2d 809, 818 (1991).
"[P]reliminary questions concerning the qualification of a person to be a witness are determined by the trial court, which is not bound by the rules of evidence in making such a determination. In determining whether a person is competent to testify, the court may consider any relevant information which may come to its attention. In re Faircloth, 137 N.C. App. 311, 316, 527 S.E.2d 679, 682 (2000) (citation omitted).
Interested Persons (N.C.R. Evid. 601(c))
"[T]estimony of a witness is incompetent under the provisions of the Dead Man's Statute when it appears '(1) that such witness is a party, or interested in the event, (2) that his testimony relates to a personal transaction or communication with the deceased person, (3) that the action is against the personal representative of the deceased or a person deriving title or interest from, through or under the deceased, and (4) that the witness is testifying in his own behalf or interest.' In re Will of Lamparter, 348 N.C. 45, 51, 497 S.E.2d 692, 695 (1998) (quoting Godwin v. Wachovia Bank & Trust Co., 259 N.C. 520, 528, 131 S.E.2d 456, 462 (1963)).
"[T]he standard of review for use in is one that involves a de novo examination of the trial court's ruling, with considerable deference to be given to the decision made by the trial court in light of the relevance-based inquiries that are inherent in the resolution of certain issues involving application of Rule 601(c), including the provisions which result in 'opening the door' to the admission of otherwise prohibited testimony. In re Will of Baitschora, 207 N.C. App. 174, 181, 700 S.E.2d 50, 55-56 (2010).