Katarina Stashyn

Katarina Stashyn testified for the Commonwealth on Day 7 about DNA testing of exercise-band swabs and stains from the exterior of the house. Under Jennifer Sprague's questioning, she explained laboratory controls and review procedures. She had performed part of the laboratory work on the swabs but had not handled the bands themselves, and she clarified that Y-STR analysis was not performed.

Stashyn reported that results from the yellow-band ends supported Dawson Clancy's inclusion under two contributor-count assumptions. The middle sample yielded separate inclusionary statistics for Dawson, Callan and Patrick Clancy despite being interpreted as a two-person mixture. She explained that shared DNA among relatives complicated interpretation and that separate statistics did not establish joint contribution. She also corrected counsel's suggestion that including Cora Clancy necessarily excluded the other four people compared.

The black-band ends were unsuitable for comparison. Its middle yielded a three-person mixture with separate statistics for five family members, including only limited support for Lindsay Clancy's inclusion. Stashyn explained that Lindsay's likelihood ratio was 11 and that validation studies had produced inclusions for known noncontributors within the range of 2 to 1,000. Exterior stains B and D yielded single-contributor profiles supporting Lindsay's inclusion; stain C was unsuitable for comparison. The judge overruled a defense objection to the statistical presentation, and Kevin Reddington declined cross-examination.