Finding Jane Doe: a forensic application of 2D image calibration

Abstract

Thirty years ago, a young girl was found decapitated. Her identity remains unknown, and neither her head nor her killer have been found. Until recently, the location of her grave was lost, preventing any efforts to identify her using modern forensic techniques. This paper presents a case study on the use of burial photos to accurately and precisely determine the location of the lost grave. We highlight challenges in finding good correspondences between points in thirty year old imagery and the actual scene today, characterize the sensitivity of a camera calibration's geometric constraints to inaccuracies in these correspondences, and discuss an interactive tool that allows an analyst to quickly identify problems with them. Using the geolocation pipeline and tools discussed in this paper, we localized the lost grave to an approximately 1.6 meter long uncertainty region. On June 16, 2013, the Saint Louis Police Department performed an exhumation according to this localization, quickly finding the body.

DEEPFOCAL: A method for direct focal length estimation

“…Methods have been proposed for camera calibration [8,3,9,10], inferring 3D layout [11,12,13], and performing metrology [14]. These methods impact a variety of fields, including environmental monitoring [15] and forensic analysis [16].…”