Opinion ID: 4543708
Heading Depth: 2
Heading Rank: 3

Heading: FBI Agent’s Testimony

Text: Based on the surveillance videos and still images, Agent Winn testified about the similarities between Caldwell (who was arrested for the BOA robbery) and the earlier Noa Bank robber. Caldwell and the Noa robber were the same sex, race, build, and height; had the same high hairline and short-cut hairstyle; wore similar clothing and a seemingly identical blue and white bandana; and used a similar looking black bag and silver and black automatic handgun. In both robberies, the robber carried his handgun in a “strange manner” by wrapping all four fingers and the thumb around the grip of the handgun, below the trigger guard, instead of placing the index finger on the trigger or on or above the trigger guard. Erica Ames, an FBI forensic examiner and DNA analyst, also testified. In 7 Case: 18-13426 Date Filed: 06/24/2020 Page: 8 of 28 her DNA report, Agent Ames compared Caldwell’s DNA to the mixtures of DNA on the bandana, wig, and handgun recovered after the BOA robbery. Agent Ames explained that, from DNA comparisons, examiners can draw three types of conclusions: inclusion, exclusion, and inconclusive. FBI examiners generate a statistic—called a “likelihood ratio”—that “helps give weight to [their] conclusions.” A likelihood ratio is “a mathematical comparison of two different explanations for the DNA evidence” that “supports the strength of the inclusion.” FBI examiners also provide a verbal description of how strong the support for inclusion is at a given ratio. Agent Ames testified that the bandana revealed a mixture of DNA from three males, and Caldwell was included as a possible contributor to that DNA mixture with a likelihood ratio of 700 billion. Because the likelihood ratio was so high, Agent Ames concluded that “Caldwell was the source of one of the contributors of the mixture from the bandana.” The wig revealed a mixture of male and female DNA from three individuals, and Caldwell was included as a possible contributor to that DNA mixture with a likelihood ratio of 480,000. Agent Ames concluded that there was “very strong support that Mr. Caldwell is a contributor to the mixture on the wig.” The handgun revealed a mixture of male and female DNA from four individuals, and Caldwell was included as a possible contributor with a likelihood ratio of 4.6 million. Agent 8 Case: 18-13426 Date Filed: 06/24/2020 Page: 9 of 28 Ames concluded that there was “extremely strong support that Mr. Caldwell is a contributor to the mixture from the . . . pistol.” Defense counsel extensively cross-examined Agent Ames on, among other things, her methods in calculating the likelihood ratios. Defense counsel introduced most of Agent Ames’s case file, including her report, which similarly stated her conclusions. On re-direct, Agent Ames confirmed her conclusions as to each piece of evidence.