3D images, known as anaglyphs are two images merged through red and blue light to give a 3D appreciation. They are useful in presenting evidence where the Court needs to appreciate the shape of an object or person. Rather than view a normal flat photograph, the anaglyph adds the extra dimension of depth.
In 2002 FVS presented anaglyphs in court to show that an object being carried was a package and not an envelope. Anaglyphs are viewed with special glasses - the right eye being for the blue filter and the left eye for the red filter. An example anaglyph is shown below, and can only be viewed with special 3D glasses (right).