Techniques used for fingerprints, handwriting, hair, and fiber analysis

Fingerprints

Ways to Lift and Reveal Fingerprints is also included in this passage:

There are nmany powders used to reveal fingerprints and lift fingerprints in an array of colors and different chemicals. Experienced crime scene workers say that the "black or grey" powder works best for latent type fingerprints. Black powder is usually made of charcoal or black carboned which is dusted onto white or light surfaces to reveal prints. Gray powder is usually mae up of alluminum dust and dusted onto dark surfaces or mirrors and metal surfaces because the surfaces will then photograph black. Powders have to be applied to a non-absorbent surface with a brush made of fiber glass or camels hair. The way these powders stick is to the oil and sweat left from the fingerprint(s). There is another powder called magna-sensitive powder that is brushed on a magnetic surface with a "magna brush" that doesn't have bristles that touch the surface. (magneitc powders are also black or gray). Latent prints can also be developed with fluorescent powders which reveals the print under ultraviolet light. These powders aren't the only thinga that reveal prints because chemicals can also do the job! The oldest technique is called "iodine fuming" which is based on "iodine has the property to sublime". Iodine is a "solid crystal" that, when heated, transforms into a vapor with out being a liquid first. The material with the fingerprint is put into a chamber with iodine crytals and when heated, it combines with the prints to make them visible. The negative aspect of this technique is the fact that once the product is released from the chamber, the prints start to fade. A solution to this problem is having the print photographed or sprayed with a 1% solution of starch and water. This will turn the fingerprint(s) blue and make the print last for weeks and maybe even months. Another chemical used other than iodine is silver nitrate. After this chemical is applied, it can be reveald with ultraviolet light (like the fluorescent powders). The science behind this reaction is sodium chloride (from the salt from perspiration) and silver nitrate combined forming silver chloride which is a colorless chemical. AFter this combination, a 3% solution is brushed onto the print and put under ultraviolet light to expose a print of a reddish-brown or black color. Ninhydrin (another chemical solution) depends on the chemical reaction with perspiration to form a purple/blue color with the amino acids from the print. An aerosol can filled with a .6% solution of ninhydrin powder and acetone or even ethyl alcohol is sprayed onto the surface where the fingerprints lie. Prints show up after an hour or two unless it is heated in an oven at 80 or 100 degrees C. Another unique chemical treatment that produces a white latent print is super-glue fuming which is exactely done as it sounds. The chemical from the glue that actually interacts and reveals the print is called cyanoacrylate ester which makes up 98% or 99% of super glue. These fumes are created when the super glue is placed on "absorbent cotten" with sodium hyroxide or heating the glue works also. The fumes and the material is put in a chamber (like ninhydrin) for up to 6 hours.

Cite:

Chow, Lawrence. "Lifting Fingerprints with Powders and Chemicals." The Bronx High School of Science. Web. 24 Aug. 2009. .

Handwriting

Slant:

Right Slant- "response to communication" (meaning they may wish to be friendly or manipulative)

Upright- Independance

Left Slant- emotion and reserve

Size: there are three "zones" classified as middle, upper, and lower for this specific area of handwriting analysis.

Large Size- "extravert and outgoing"

Small Size- (opposite of Large) shy and to themself

Small and Delicate Size- bad communicator

Pressure:

Heavy Pressure- committed and takes things seriously

Light Pressure- sensitive and empathetic

Upper Zone/Case:

Tall Upper Strokes- reaching towards goals and ambitions

Upper Zone Loops- likes to "think things through" and use imagination

Upper Up-Stroke Returning on top of itsself- "squeezing out imagination" and just getting down the task at hand

Lower Zone: (Lower Loops tend to vary)

Straight Stroke- "gets the job done"

"Cradle" Lower Stroke- avoidance of aggression and confrontation

Full Loop with Heavy Pressure- energy, makes god money, sensual

Full Loop with Low Pressure- need or wish for security

Word Spacing:

Wide Spaces- (literal) "give me space"

Narrow Spaces- wishes to be with others

Middle Zone: egotistical


Citation:

"Graphology, handwriting analysis - how graphologists and handwriting experts analyse handwriting - free graphology techniques and theory training." Businessballs free online learning for careers, work, management, business training and education: find materials, articles, ideas, people and providers for teaching, career training, self-help, ethical business education and leadership; for personal, career and organizational development. A fun free online college of ethical life and work education, for self help, teaching, careeer development, distance learning, organizational development, with team building games and exercises, free self-help and training ideas, free management theories, free diagrams, templates, samples, examples, materials and tools, free child development activities and adults development exercises ideas. Web. 31 Aug. 2009. .

Hair

To prepare for a hair analysis (for medical use), hair should be washed and stripped of hair care products. Then a sample is taken to a lab for testing:

Hair is usually taken where it is grown close to the skin like pubic hair or neck hair because it shows what is more recent and what has been recentely occuring in the body. Special chemicals wash the hair before tested. The hair must be plucked for there to be DNA which is at the end of the hair.

Cite:

"Hair Analysis." WebMD - Better information. Better health. Web. 07 Sept. 2009. .