Category Archives: Fingerprints

Crime Scene Investigation and Fingerprinting

Interesting historic video on crime scene investigation and forensic science. I have a copy as well, that I purchased on DVD from the National Archives. The date on the original is a bit unclear, but it appears to have been made around 1960. It should be noted that some of the practices shown are no longer up to date, and that current safety precautions are not in use. It’s still interesting from a historical standpoint.

Magnetic Powder

By Pat A. Wertheim

This article originally appeared in Minutiae, the Lightning Powder Co. Newsletter, #43, July-August 1997.

Even though magnetic powder has been available since the early 1960’s, many latent print examiners and crime scene technicians are still not using it to full advantage. Magnetic powder adds a wide range of flexibility to one’s resources. In general, magnetic powder is used on non-magnetic surfaces, and regular powder on iron-based surfaces. However, regular fingerprint powder is inappropriate for some surfaces, including many plastics and textured surfaces, where magnetic powder develops latent prints very well. Textured surfaces such as vinyl imitation-leather or lightly textured automobile dashboards or door panels often respond well to magnetic powder, where regular powder would pack into the low places in the texturing and make development of a good latent impossible. In addition, using the “hot breath” technique, also known as “huffing” works better with magnetic powder than with regular powder. Continue reading

Ninhydrin Processing

By Pat A. Wertheim

This article originally appeared in Minutiae, the Lightning Powder Co. Newsletter, #45, November-December 1997.

Perhaps the most productive and cost-effective method of developing latent fingerprints on paper is treatment with Ninhydrin. Freshly-mixed Ninhydrin solutions are less expensive and more dependable than premixed aerosol cans or pump spray dispensers. While the premixed containers are ready for instant use when purchased, safety experts today caution against spraying and instead encourage either dipping or painting to apply the solution.

The problem with spraying Ninhydrin solutions is that, even in a fume hood, airborne particles of Ninhydrin dust can form as the carrier evaporates. These microscopic particles may not be effectively removed from the lab by the fume hood, and may find their way back into the air you breathe. Since Ninhydrin reacts with amino acids, any exposure to your body, especially to your eyes or lungs, could have serious results. This potentially dangerous exposure is minimized by dipping or painting. Continue reading

Atmospheric Superglue Method

By Pat A. Wertheim

This article originally appeared in Minutiae, the Lightning Powder Co. Newsletter, #44, Sep-Oct 1997.

Some latent print technicians believe superglue should be listed second only to powder as the most effective latent print development technique. Others believe it should come first. Either way, no one can deny that superglue fuming is the most revolutionary new method to be discovered since the invention of powder. Superglue fuming works on many surfaces where powder is ineffective, such as plastics, and has the advantage of fixing the print on the surface for later presentation in court. Continue reading

Fingerprinting the Dead

by Daryl W. Clemens

Plastic Tape

Plastic Tape

Obtaining fingerprints for identification is a long established law enforcement practice. When the practice started, is was most common to use printers ink applied to the fingers which were then pressed onto paper cards. Later specialized inks were employed to improve the quality of the prints obtained. While ink is still used today, many agencies are now using computer “live-scan” methods to record reference prints. Continue reading

Latent Prints in Dust

by Captain Curtis C. Frame,
Criminal Investigation Division
Jasper County Sheriff’s Office
Jasper, Texas
Article Copyright © 2000, Curtis C. Frame

A Latent print found in dust, may be the only clue to a case in which there are no other leads. And because the areas that are routinely touched by the victims are not normally dusty, the dust print we find may be the only link we have of the perpetrator to the crime scene. However, most crime scene and latent print examiner experts will say that, regardless of their importance, latent prints in dust are a nightmare. This is due to the fact that a latent print in dust was actually left there due to the dust being removed by adhering to the ridges of the skin that touched it. Continue reading

Black Powder Processing

By Pat A. Wertheim

This article originally appeared in “Minutiae”, The Lightning Powder Co. Newsletter, No. 42, May-June 1997, p. 6.

Although old-fashioned black powder is the workhorse of fingerprint development
techniques for crime scene use and is also an important method in the laboratory,
maximizing the effectiveness of powder requires far more sophistication than
simply dipping a brush into the jar of powder and painting it onto a surface.

More control can be exercised over black powder by working out of a shallow
dish. The perfect disposable dish can be made by cutting or tearing a blank
inked fingerprint card from any edge into the center of the card. Overlap
the two edges of the cut by about an inch (two or three centimeters) and
tape the card back together to make the dish. A large laboratory weighing
dish may be used, or any other shallow dish or bowl. Place one-half to one
teaspoon of powder (approximately one millilitre) into the dish. Continue reading

Hidden Evidence: Latent Prints on Human Skin

By Ivan Ross Futrell
Mr. Futrell is a supervisory fingerprint specialist in the Latent Fingerprint
Section of the FBI Laboratory in Washington, D.C.

This Article Originally Appeared in the FBI Law Enforcement Bulletin, April 1996.

(Recent research proves that identifiable prints can be obtained from the
skin of homicide victims under real field conditions, not just in the

Whether to stop them from fleeing, immobilize them, or dispose of them, murderers
often grab their victims. What homicide detective has not wished for the
ability to develop identifiable fingerprints of a suspect from the skin of
a dead body? Crucial fingerprint evidence linking the perpetrator to the
victim must be right there, but, until recently, attempts to retrieve those
prints rarely met with success. Continue reading

Case Study: Conviction Through Enhanced Fingerprint Identification

This article originally appeared in the FBI Law Enforcement Bulletin, December 1992.

In March 1990, an unknown assailant sexually molested and fatally stabbed a young woman. At the crime scene, an investigator discovered few leads. The only evidence was a pillowcase, found adjacent to the victim’s body, that exhibited several bloodstains. One stain showed some faint fingerprint ridge detail, barely visible even to the trained eye. Continue reading