Determining Suspect Height from Photogrammetry and Adjustable Bipedal Rig

Deriving suspect height from video and still images can be a problematic obstacle. The most accurate methods available to the forensic community currently are still plus or minus one inch, including photogrammetry. However, these methods only consider the top of the suspect’s head for height analysis. They do not consider the unique proportions and features of a person, and they also do not take into consideration the unique shapes and positions the body can form while walking and running. While walking or running, the top of the human head moves up and down depending on where the person is in their stride.

This study attempts to account for this by using photogrammetry alongside two custom bipedal rigs, one male and one female. These custom bipedal rigs allow for height adjustment as well as individual positioning of the body and limbs to better match to suspect during photogrammetry analysis. In addition to this, when the height of one of the bipedal rigs is adjusted, the limbs grow or shrink proportionally to the standard percentile ranges in Henry Dreyfus’s “Measure of Man and Woman”.

This study attempts to determine if body and limb positioning can increase accuracy when using photogrammetry to determine suspect height. The suspect’s heights were measured using a verified stadiometer to determine actual height. The suspects were then filmed walking and running across a predetermined area. Individual frames taken at different positions and distances from the camera, as well as during different parts of a suspect’s stride. These frames were then analyzed for suspect height, using photogrammetry and the custom bipedal rigs, independently by a group of analysts that were not informed of the reported stadiometer heights. These heights determined from the photogrammetry and bipedal rigs were then compared and analyzed against the reported stadiometer heights.