Abstract
Researchers widely use three-dimensional (3D) printing in architecture, public safety, and forensics. In forensic anthropology, they create high-resolution 3D reproductions of skeletal remains and precise negative space renderings. Literature supports the reliability of 3D imaging and printing to enhance tool mark evidence, particularly through computed tomography (CT) and micro-CT (Baier et al., 2017; Carew et al., 2019). Studies further validate that 3D structured light scans and prints accurately supplement traditional skeletal documentation (Shanley et al., 2024). With the growing use of 3D models as courtroom demonstratives, this study evaluates whether downsizing a skull can produce scientifically valid and cost-effective results.Unlike studies that relied on CT and micro-CT, this pilot study utilized coordinate measuring machine (CMM) technology through the FARO Design 3D ScanArm and RevEng software. This method ensures maximum accuracy with high precision and tight tolerance for the resulting 3D prints. I used the Formlabs 3L printer with White V4 resin, Form Wash L (99% isopropyl alcohol), Form Cure L, and Preform software. I selected White V4 resin for its superior precision with the Formlabs 3L. I scanned a plaster cast of Genocidaire Francisco Pizarro, scaled it from 1.0 to 0.2, and printed it in resin.
The resulting 3D rendering provided reliable comparative metrics, measuring between 17.6% and 22.2% of the original, with an average of 20.3%. These values correlated strongly with the original measurements (r = 0.997, p < 0.001). The accuracy stayed within ±1 mm, meeting acceptable standards for demonstrative aids (Stull et al., 2014). Grounded in sound methodology and adhering to Daubert standards (Robinson, 2023), this study confirms the forensic utility of scaled 3D models and showcases their potential to transform evidentiary practices.