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  • PrinTips 11—An Overview of Latent Print Development Powders

    By: Administrator
    Latent print powders come in five different formulations: Regular-Oxide, Metallic, Magnetic, Combination and Fluorescent. This article covers the basic theory of each type. By: Don Penven, Tech Support Latent print powders come in five different formulations: Regular-Oxide, Metallic, Magnetic, Combination and Fluorescent. This article covers the basic theory of each type. Keep in mind that if you are uncertain which powder to use on a particular surface—experiment by placing your print in an...
  • PrinTips10-Cyanoacrylate (CA) Fuming

    By: Administrator
    Super Glue gained fame for its incredible tenacity, but nearly 20 years passed before this product found its way into the field of forensic science. Scientists in Tokyo’s National Crime Laboratory discovered that white fingerprints kept appearing on bottles of Cyanoacrylate Cyanoacrylate or Superglue fuming is a common practice in crime labs and crime scenes. Cyanoacrylate adhesive, better known as superglue, was first discovered by Harry Wesley Coover Jr., who was experimenting with...
  • PrinTips09 Adhesive-Side Latent Print Development

    By: Administrator
    Duct tape has become the criminals bonding method of choice—investigators find it used on hostages, rape and kidnap victims and other innocent bystanders. Developing latent prints on the adhesive side of tapes There’s an expression among the “fit-it” community that goes like this, “If it doesn’t move and it should—use WD-40. If it moves but shouldn’t—use duct tape.” The criminal element seems to have adopted the latter advice. Duct tape has become the bonding method of...
  • PrinTips 8 Small Particle Reagent (SPR)

    By: Administrator
    References to Small Particle Reagent (SPR) began appearing in the literature dealing with latent print development during the late 1980s. References to Small Particle Reagent (SPR) began appearing in the literature dealing with latent print development during the late 1980s. The odd-sounding name is derived from the fact that the prime ingredient in SPR is a very finely-ground form of molybdenum disulfide. The popularity of this reagent draws from the fact that it is an ideal medium for...
  • PrinTips07 Oil Red O

    By: Administrator
    Andre Beaudoin, Sûreté du Québec, developed a method that makes the recovery of fingerprints on wet porous surfaces simple and easy using Oil Red O. Oil Red O—For Developing Latent Prints on Wet Paper Sounds like a weird name for a latent print development reagent, but this chemical is finding its way into crime labs throughout the world. Amino acids dissolve in water, and, therefore, fingerprints on porous surfaces that have been exposed to moisture (water) usually do not respond well...
  • PrinTips06 Physical Developer

    By: Administrator
    As effective as they may be, Iodine fuming, DFO and ninhydrin do not always produce desirable results. The blessing here is that these chemicals do not interfere with subsequent development with Physical Developer. When all else fails, knowledgeable crime lab technicians turn to Physical Developer In the 1970s, the new kid on the block of latent print development chemicals was Physical Developer. As effective as they may be, Iodine fuming, DFO and ninhydrin do not always produce desirable...
  • PrinTips05 Silver Nitrate

    By: Administrator
    Silver nitrate combines with the latent print moisture present on a document. The result is that when salt, sodium chloride, is present in the perspiration the silver combines with the chloride atom of salt to form silver chloride. Using Silver Nitrate for Latent Print Development Silver Nitrate has been used for over 75 years as a latent print development technique. In 1937, M. Edwin O’Neill published, “The Development of Latent Fingerprints on Paper,” in which the author mentions the...
  • PrinTips04 Ninhydrin Development

    By: Administrator
    Like many of the techniques used in crime labs and crime scenes, ninhydrin (also known as 1,2,3-indantrione monohydrate) was not specifically used for developing latent prints. Ninhydrin: 2,2-Dihydroxyindane-1,3-dione, a Reagent Sensitive to Amino Acids Like many of the techniques used in crime labs and crime scenes, ninhydrin (also known as 1,2,3-indantrione monohydrate) was not specifically used for developing latent prints. The first mention of ninhydrin in chemical literature was in 1910....
  • PrinTips03 Latent Print Development Using DFO

    By: Administrator
    This article will cover DFO (1,8-Diazafluorene-9-one), which is a Ninhydrin analog, and it too reacts to amino acid residues in latent prints. DFO: An alternative to Ninhydrin Several very effective methods are available for latent print development on porous materials. Iodine fuming was discussed in PrinTips-02. This article will cover DFO (1,8-Diazafluorene-9-one), which is a Ninhydrin analog, and it too reacts to amino acid residues in latent prints. Ninhydrin has been a mainstay for latent...
  • PrinTips02 - Iodine Fuming

    By: Administrator
    It is widely believed that Iodine fuming was the first, or at least among the first chemical methods for developing latent fingerprints. Iodine is a non-metal, crystalline element that was first isolated in 1811 by the French chemist Barnard Courtois. Latent Print Development Using Iodine Fuming  It is widely believed that Iodine fuming was the first, or at least among the first chemical methods for developing latent fingerprints. Iodine is a non-metal, crystalline element that was first...
  • PrinTips01 - Magnetic Latent Print Development Methods

    By: Administrator
    Magnetic latent fingerprint powder was first introduced in the 1970s. Since then it has enjoyed widespread use among crime scene units around the world. Magnetic powder has several major benefits for the user: Magnetic latent fingerprint powder was first introduced in the 1970s. Since then it has enjoyed widespread use among crime scene units around the world. Magnetic powder has several major benefits for the user: It makes crime scene clean-up so much simpler. It is very economical since...