Does anyone remember what type of surface the shoe print was found on? I am remembering carpet, but could be totally wrong. According to the article below, amido black is most reliable on non porous surfaces, not so much on others:
“Amido black is very sensitive and works well on non-porous surfaces but its high background color (light to medium blue) compromises contrast on multi-colored porous surfaces.
Amido Black is a protein stain, and as such should not be considered as even a presumptive test for blood, let alone a confirmatory test. The protein may be present in other body fluids, in addition to blood. However, other actual presumptive tests may be successful after the application of amido black.”
This article reviews three popular methods for blood print enhancement: Amido Black, Leuco Crystal Violet (LCV) and Hungarian Red
www.crime-scene-investigator.net
Interested in other opinions about this.