Paul W. Barnes, Sr. v. State of Indiana (mem. dec.), 39A01-1610-CR-2313

Defendant Paul W. Barnes, Sr., B.B.’s grandfather, was tried for two counts of level‑1 child molesting based on alleged incidents on Feb. 21–22, 2015.
B.B., age 10, testified to repeated sexual contact; she wrote a contemporaneous note to her mother and reported baby powder observed on her genital area.
Forensic testing of external genital swabs recovered sperm cells; the major DNA profile matched Barnes and was reported as extremely rare.
Defense put forward an alternative explanation (Barnes claimed he masturbated and accidentally wiped semen on B.B.’s underwear); Barnes testified and denied the molestation.
During trial the State sought to call a forensic interviewer (Stephanie Back) to testify that B.B. showed no signs of coaching during the interview; the court permitted the testimony after concluding Barnes had “opened the door.”
Jury convicted Barnes on both counts; he received concurrent 40‑year executed sentences. On appeal the court held the trial court abused its discretion in admitting the vouching testimony but deemed the error harmless given independent evidence of guilt.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Barnes "opened the door" to expert testimony that B.B. showed no signs of coaching	State: Defense theory (that repeated questioning produced B.B.’s account) would attack credibility in closing, permitting rebuttal about coaching	Barnes: At the time State sought Back’s testimony, defense had not introduced evidence suggesting coaching or otherwise attacked B.B.’s credibility	Court: Barnes did not open the door; permitting Back to vouch was an abuse of discretion
Whether admission of Back’s vouching testimony was reversible error	State: Testimony rebutted defendant’s implicit claim and was cumulative to other evidence	Barnes: Vouching directly affected witness credibility, which was central to the case	Court: Error was harmless — independent, substantial evidence (DNA, corroborating brother testimony, inconsistencies in Barnes’s accounts) made it unlikely the testimony contributed to the verdict

Hoglund v. State, 962 N.E.2d 1230 (Ind. 2012) (standard for abuse of discretion in evidentiary rulings; harmless‑error framework)
Sampson v. State, 38 N.E.3d 985 (Ind. 2015) (expert testimony on signs of coaching generally impermissible vouching unless defendant opens the door)
Clark v. State, 915 N.E.2d 126 (Ind. 2009) (‘‘opening the door’’ permits otherwise inadmissible rebuttal testimony to correct misleading impressions)
Steward v. State, 652 N.E.2d 490 (Ind. 1995) (once a child’s credibility is challenged, expert testimony about reliability may be appropriate)
Norris v. State, 53 N.E.3d 512 (Ind. Ct. App. 2016) (admission of interviewer testimony about lack of coaching was an abuse where no prior evidence challenged coaching)
Hamilton v. State, 49 N.E.3d 554 (Ind. 2016) (defendant did not open the door to coaching testimony where attack on credibility was insufficiently developed)
Hubbell v. State, 754 N.E.2d 884 (Ind. 2001) (errors in admission/exclusion of evidence are harmless unless they affect substantial rights)