How to Get a Fingerprint if the Individual Is Deceased and Rigor Has Set In

Fingerprint cards help organize evidence collected in an investigation.

For over a century, scientists and investigators have been using fingerprints' uniqueness to identify persons and solve crimes. Corpses often must be fingerprinted to allow for the positive identification of victims. But corpses that are in a state of rigor are unbending and uncooperative, and their fingers may be more difficult to roll or press to extract fingerprints. With a little creativity and patience, however, clear and useful fingerprints can be extracted using many of the same materials already used in fingerprint extraction.

Things You'll Need

• Hand of a deceased human
• Black fingerprint powder
• Fingerprint powder brush
• Clear tape
• Fingerprint card or heavyweight white cardstock

Instructions

Breaking the Rigormortis

1. Hold the deceased's hand in your right hand.

2. Grab the curled finger with your left hand, placing the four fingers on top of the curled finger, and placing the thumb under the deceased finger's knuckles or joint.

3. Use the thumb as a lever fulcrum and apply even pressure with the pointer and middle fingers of the left hand to snap the joints straight.

4. Repeat these steps at all curled joints.

Taking the Fingerprint

1. Cut ten pieces of clear tape, each large enough to cover one of the fingers.

2. Use the powder brush to gently cover a fingertip with black fingerprint powder.

3. Tap the finger gently to remove excess powder.

4. Place the small piece of tape over the fingerprint on the tip, starting in the center and gently smoothing out the tape over the print. Once the tape has been placed on the finger, do not move it, so that there is no smudging.

5. Remove the tape carefully, and stick it to a white fingerprint card or other white cardstock, making sure the fingerprint is clear and visible.

6. Repeat the previous steps which each finger to make a matching set.

Tips & Warnings

• It may be preferred, once the rigor is broken, to use ink and paper to take the print instead of tape. In this case, simply cut the paper into small squares and use them in the same manner as the tape.

• This process only works if decomposition has not set in. If decomposition has begun, the whirls of the fingerprint may be damaged, so more complex procedures are necessary to extract a useful fingerprint.

References

• "The Science of Fingerprints: Classification and Uses"; U.S. Federal Bureau of Investigaton; 1988