This technique was described by the Maine State Police Lab in the January-February-March 1989 issue of Identification Canada. Ortho-tolidine reacts to a blood component by giving blood a deep blue-green color. This feature enhances latent fingerprints that consist of bloody deposits left on the skin of the cadavers, depending somewhat on the skin color. This solution forms a slim film on the skin; it sticks to the lifter and makes it possible to lift the fingerprint developed by the ortho-tolidine treatment. The technique is effective if the cadaver has no sweat or other traces of humidity and has not been washed or otherwise exposed to humidity. Therefore, the cadaver should be covered at all times with a dry sheet or cloth. It should not be placed in an airtight or unventilated wrapping. The skin must be in good condition, smooth, and devoid of hair or bristles. Biological analyses must be performed before the use of the ortho-tolidine technique. The solutions used are toxic and highly flammable; one is likely to explode if not kept under the conditions recommended by the manufacturer. Step-by-step instructions, photographs, and case examples