Fingerprints Fingerprints What are fingerprints Friction ridge skin
- Slides: 19
Fingerprints
Fingerprints What are fingerprints? § Friction ridge skin pattern § Found on fingers, palms, toes, soles of feet. Composed of ridges (hills) and furrows (valleys) § Black = Ridges White = Valleys
Fingerprints What are fingerprints? § § § Develop in early embryonic development. Pattern based on genetics, detail somewhat random Identical twins do not have identical fingerprints
Fingerprints How are fingerprints analyzed? Categorized by pattern and minutiae
Fingerprints How are fingerprints analyzed? Patterns Arch Loop Whorl
Fingerprints How are fingerprints analyzed? Minutiae Bifurcation Dot Ridge Ending Island
Fingerprints There are 3 types of fingerprints Visible – left by dirt, grease, blood, etc. 1. § Does not need processing
Fingerprints There are 3 types of fingerprints Impression – indentation in soft material (butter, putty, tar, etc. ) 2. § Does not need processing
Fingerprints There are 3 types of fingerprints 3. Latent – requires processing to make visible and suitable for analysis
Fingerprints > Analysis What are the invisible components? Multiple sweat glands secrete onto fingers, palms, etc. Sweat contains: § § Inorganic ions (Na+, Cl -) Proteins, amino acids § § Lipids Other
Fingerprints > Analysis Physical Development: Dusting § Apply powder to latent print or area. § Powder adheres to print. Brush and Powder
Fingerprints > Analysis Chemical Development: Silver Nitrate 1. § § No longer used often (messy, not sensitive) Silver reacts with Cl - ions in print
Fingerprints > Analysis Chemical Development: Iodine Fuming 2. § § § Iodine sublimes (solid → gas) Iodine reacts with lipid components; becomes trapped in the print. Fuming wand or chamber Dirty Brown Color
Fingerprints > Analysis Chemical Development: Ninhydrin 3. § § § Reacts with amino acids; purple color Painted or sprayed on area Heated to react
Fingerprints > Analysis Chemical Development: Super glue fuming 4. § § § Fumes with heat or base (Na. OH) Fumed in cabinets Off-white print
Fingerprints > Collection of prints: Tape lift: § § Tape placed over developed print Tape then placed on white card.
Silver nitrate fingerprinting Dip finger in salt water n Let air dry n Press finger onto piece of paper n Put a drop of silver nitrate onto paper n Put under black light for 10 minutes n
Iodine fuming finger prints Rub finger on oily part of skin n Press finger onto piece of paper n Place paper in beaker with iodine crystals n Cover back up n Remover paper in 5 minutes n
- Mikael ferm
- Are impressions left by friction ridge skin on a surface
- When climbing where do you need high friction
- The study of the uniqueness of friction ridge structures
- The inner terminus of the finger print pattern.
- Negative skin friction on a pile
- Reynolds colburn analogy
- Ridges characteristics
- Fingerprint ridge characteristics
- Thin skin vs thick skin
- Milady chapter 23 textbook
- Organum germinativum
- Principle of fingerprint
- Aplusphysics dynamics-friction answer key
- Kinetic friction definition
- Friction
- Friction
- Frictional force
- Gatke material
- Roadside friction