The first article has Michigan ties. Following up on a cold case led an Ohio medical examiner’s office to a fingerprint match and old files in Grand Haven that ID’d a man killed by a train in 1980. Via The Grand Haven Tribune
The second is another story of using ancestral DNA, this time to identify an abandoned child, which led to clearing a cold case on the other side of the country. From Forensic Magazine
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.
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 →
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 →
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 →
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 →
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 →