Evidence Collection

The ABFO No. 2© Scale was designed by the American Board of Forensic Odontology and is used through the country when photographing bite marks on a victim’s body. The three cross-hair circles are useful in helping to compensate for distortion resulting from oblique camera angles. The graduations are all metric, except for the width of the legs, which are 1” wide. The 1 cm division lines are traced and extended across the photographic print to grid an image. Measurements within the image are then made relative to these inscribed 1 cm grid lines to compensate for any distortion resulting from non-parallelism between the film and the object planes.

ABFO No. 2© Specifications:

• Rigid, L-shaped piece of laminated plastic 1 mm thick
• Millimeter markings accurate to 0.1 mm or better
• Overall size is 105 mm x 105 mm (about 4" x 4")
• Gray areas have a reflectance value of approximately 18%
• Alternating black and white bars (1 cm) to permit measurements from grossly over- and underexposed photographs.