Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Forensic 2 Sem1
Review for Forensic Science 2 from 8/12/24 - 12/20/24
| Question | Answer |
|---|---|
| What are some common hazards in forensic science? | Infectious human blood and bodily fluids, toxic chemicals, hypodermic needles, broken glass, other sharps |
| What are the routes of exposure to hazards in forensic labs? | Inhalation, skin contact, ingestion, injection |
| What are the federal and state regulations related to laboratory safety? | Personnel must be informed and trained on chemical hazards, supervisors ensure safety precautions are followed |
| Who develops, implements, and enforces safety standards in forensic science? | Occupational Safety and Health Act of 1970, National Institute for Occupational Health (NIOSH), Environmental Protection Agency (EPA) |
| What are chemical hazards? | Corrosive materials, radioactive substances, carcinogens, biohazards, compressed gases, toxic chemicals, reactivity chemicals, flammable substances |
| What health and safety hazards are present in forensic labs? | Flammable materials, explosive materials, pyrophoric materials, oxidizers, corrosive materials |
| What information is found in a Material Safety Data Sheet (MSDS)? | Hazardous properties, disposal techniques, personal protection, packaging and shipping procedures, emergency procedures for spills/exposure |
| How are chemicals labeled for safety? | Labels are the primary warning source, with mandated information from federal and state regulations |
| How are chemical hazards portrayed on labels? | Picture hazard, symbol hazard, word hazard |
| How is chemical waste collected and disposed of? | EPA regulates disposal; improper disposal can lead to fines or jail |
| What are biological hazards in forensic science? | Body fluids, tissue, and biological specimens that may contain bloodborne pathogens like HIV, AIDS, and Hepatitis |
| What are universal precautions in forensic labs? | Treat all body fluids and materials as if infected, use engineering controls like biohazard bags, puncture-resistant containers, long-handled mirrors |
| What protective measures should be taken in forensic labs? | Barrier protection (gloves, coveralls, shoe covers), eye/face protection, sharp containers, no eating/drinking/applying cosmetics, hand washing, respirators for airborne hazards |
| How can contamination and transfer be avoided in forensic labs? | Decontaminate tools/equipment with disinfectants (e.g., bleach diluted 1:10, 70% isopropyl alcohol), allow sufficient contact time |
| How is biological waste handled and disposed of? | Biohazardous waste (cadaver waste, human blood/tissues) must be stored and disposed of separately from regular waste |
| What are other classes of hazardous materials in forensic labs? | Carcinogens (cancer-causing agents), teratogens and mutagens (cause DNA mutations/genetic damage), compressed gases (flammable/explosive), radioactive materials (used in assays), cryogenic materials (e.g., liquid nitrogen) |
| What are the types of Personal Protective Equipment (PPE)? | Hand Protection, Eye Protection, Foot Protection, Respiratory Protection, Head Protection |
| What is the purpose of hand protection in PPE? | Selected based on material hazards, checked for tears or holes, minimize contamination while wearing gloves |
| What is required for eye protection in the lab? | Safety glasses/goggles for biological, chemical, and radioactive materials, face shields for splashing or flying debris, no contact lenses, worn over prescription glasses |
| What is required for foot protection in the lab? | Shoes covering and protecting the feet, used to prevent injuries from falling objects, electrical hazards, and contamination, non-permeable shoe covers can be used |
| When is respiratory protection necessary in the lab? | In bombings, clandestine laboratories, and when organic solvents produce noxious fumes or airborne contaminants |
| What is head protection used for in the lab? | Required at crime scenes like bombings where structural damage may have occurred |
| What laboratory safety equipment is required by federal laws? | Safety shower, fire-extinguishing materials, blankets, handheld extinguishers, hoses, eye bath, first aid kits |
| What is the function of a ventilated fume hood? | Extracts fumes and hazards away from technicians and vents them to a safe area |
| What are the laboratory exposure control plans for chemical spills? | Procedures for handling acid, mercury, solvent, radioactive chemical spills, warn personnel and minimize contamination spread |
| What is a chain of custody (COC)? | An unbroken trail of accountability ensuring the security of samples, data, and records, including signatures or initials, dates, and identifiers for each transfer |
| Why is a chain of custody necessary? | It reduces sample mix-ups, contamination, tampering, and ensures legal defense by showing accurate analytical procedures and verifying sample identity |
| What should be included in a chain of custody during transportation? | Name and address of requesting company, list of samples with IDs, type of sample, manner of collection, tests requested, name of testing lab, relinquishing and receiving signatures |
| What must be done when receiving samples at the lab? | Verify sample integrity, ensure documentation is complete, confirm sample IDs match, check preservative/storage temperature, and refuse samples if there are discrepancies |
| What information should be logged for evidence? | Date collected, date received, unique lab ID number, original field number, required analyses, and signature/initials of person logging |
| How should samples be stored to ensure proper handling? | Store samples to minimize degradation/contamination, secure from tampering, and in an area with limited access |
| Should the sample log be computerized or handwritten? | This depends on lab policies; both methods can be used, but maintaining secure, accurate logs is essential |
| What does questioned document examination involve? | Examining writing materials, inks, alterations, sequencing of writing, paper and ink comparison, and identifying authorship or source of the document |
| What are some crimes associated with questioned documents? | Contested wills, forgery, embezzlement, breaches of contract, extortion, robbery, suicide, homicide, kidnapping |
| How should document evidence be collected? | Avoid excessive handling, place in a clean envelope, label appropriately, and mark containers, not documents, unless absolutely necessary |
| What are exemplars in questioned document examination? | Known samples of handwriting or materials used for comparison with questioned material |
| How should exemplars be chosen? | Use similar writing instruments, paper, and wording; collect with minimal distraction and ensure natural writing variations |
| What are the types of writing instruments identified in questioned documents? | Ballpoint pens, fountain pens, fiber-tip pens, pencils |
| What characteristics are examined for paper identification? | Color, size, shape, watermarks, thickness, weight, inclusions, surface appearance, and fluorescence |
| What are the common ink classifications? | Ballpoint, liquid, printing, and typewriter inks |
| How is ink analyzed and compared? | Through color comparison, chemical composition, infrared absorption, luminescence, and thin-layer chromatography |
| How is ink dating done? | Using high-performance liquid chromatography or gas chromatography-mass spectroscopy to measure volatile components in ink |
| What does handwriting comparison involve? | Analyzing individual and class characteristics to determine if questioned writing matches known samples |
| What are class characteristics in handwriting? | Gross features like letter forms, letter dimensions, punctuation, and connections between letters |
| What are individualized characteristics in handwriting? | Unique features like characteristic letter forms, strokes, and flourishes developed over time |
| What factors affect handwriting characteristics? | Speed of writing, health, age, drug or alcohol use, and attempts to disguise writing |
| What additional factors should be considered in handwriting? | Spacing, alignment, margins, spelling, phraseology, and grammar |
| How are photocopies analyzed in questioned document examination? | Determining the type of photocopying process, the machine used, and whether specific copies were made by the same machine |
| What are the methods of photocopying processes? | Chemical (light-sensitive paper), thermal (heat), and electrostatic (selenium-coated metal plate) |
| How are alterations, erasures, and obliterations examined? | Using fingerprint powder, UV or infrared light, and comparing writing materials or spacing |
| How is indented writing analyzed? | Using oblique lighting, fluorescent powder, electrostatic document apparatus (ESDA), or iodine vapor |
| What are the methods for counterfeit currency detection? | Examining the weight of paper, watermarks, metal strips, colors, and intricate designs |
| What is digital evidence? | Digital evidence includes cameras, computers, laptops, tablets, cell phones, flash drives, MP3 players, calculators, and digital planners |
| Why is examiner training important in digital evidence examination? | Examiners must be trained to follow accepted forensic procedures and conduct proper examinations |
| What are the four steps in the digital evidence examination process? | Preparation, Extraction, Analysis, and Conclusion |
| What is involved in the preparation of digital evidence? | Prepare a working directory on separate media for evidentiary file recovery or extraction |
| What is the difference between physical and logical extraction? | Physical extraction recovers data across the entire drive, ignoring file systems. Logical extraction recovers data based on the file system present on the drive |
| What methods are used in physical extraction? | Keyword searching, file carving, and extraction of partition tables and unused space |
| What is keyword searching in digital evidence examination? | A method used to search for specific keywords across the physical drive to identify data not accounted for by the operating system |
| What is file carving? | A technique that recovers usable files and data from a drive, even if the files are not listed by the operating system |
| What is logical extraction used for? | Extracting data from areas like active files, deleted files, file slack, and unallocated space, based on the file system present |
| What types of data are extracted during logical extraction? | Data from the file system such as directory structure, file attributes, file names, timestamps, file sizes, and locations |
| What is timeframe analysis? | Analyzing timestamps and system logs to determine when specific events occurred on the system |
| What is data hiding analysis? | Detecting concealed data, such as mismatched file headers/extensions, encrypted files, or hidden partitions |
| What is steganography in the context of digital evidence? | The practice of hiding data within files or systems, which can be detected during data hiding analysis |
| How can ownership and possession be determined in digital evidence? | By analyzing timestamps, file names, hidden data, and passwords to link files to a specific user |
| Why is drawing conclusions important in digital evidence examination? | Individual findings may not be sufficient on their own; conclusions must be based on the totality of the extracted data and analysis |
| What term describes all physical materials examined in the forensic laboratory? | Physical evidence (synonym for trace evidence) |
| What are common collection methods for trace evidence? | Lifting (using tape), scraping (dislodging materials onto clean paper), vacuum sweeping (vacuum with a filter trap), combing (comb or brush hair and debris), clipping (fingernails and scrapings packaged separately) |
| Why is microscopy used in forensic analysis? | To view and compare small evidence |
| What are types of microscopes used in forensic analysis? | Basic low power microscope, specialized microscopes, comparison microscope |
| What is a comparison microscope? | An instrument that uses two compound microscopes joined by a bridge to view images side-by-side |
| What are some specialized microscopes used for trace evidence analysis? | Low power stereo microscope, polarized light microscope, phase contrast microscopes, scanning electron microscopy, X-ray fluorescence spectrometry, X-ray diffraction, vibrational spectroscopy, pyrolysis gas chromatography, microspectrophotometry |
| What are some factors considered when analyzing forensic paint? | Case issues, sample size, complexity and condition, environmental effects, sample collection methods |
| How is paint typically analyzed in forensic cases? | Sample prep, layer analysis, UV-visible microscopy, infrared spectrophotometry, electron microscopy |
| How is glass identified in forensic analysis? | A: By three physical characteristics: conchoidal fracture, amorphous structure, isotropism |
| What are the layers of a human hair? | Medulla (inner layer), Cortex (middle layer), andCuticle (outer layer) |
| What is the typical hair growth cycle? | Anagen: Growth phase, Catagen: Shrinking phase, and Telogen: Resting phase |
| How is hair examined in forensic investigations? | By determining color, length, diameter, pigment granules in the cortex, medulla structure |
| How can the origin of hair be determined? | By examining the cuticle, cortex, and medulla, and considering species and racial origin |
| What are the two types of fibers commonly encountered in forensic analysis? | Natural fibers (from plant or animal materials, e.g., cotton, wool, silk), synthetic fibers (man-made, e.g., nylon, polyester, rayon) |
| What is fingerprint examination? | The study, classification, development, and comparison of fingerprints for identification |
| What are the three layers of the skin? | Epidermis, dermis, hypodermis |
| What is the function of the dermis? | It contains blood vessels and provides nutrients to the epidermis |
| What are the three basic principles of fingerprints? | Individual characteristics, remain unchanged, have ridge patterns for classification |
| What are the three basic ridge patterns of fingerprints? | Loops (60%), whorls (35%), arches (5%) |
| What is the Henry System? | A fingerprint classification system used by Scotland Yard and modified by the FBI |
| What are the eight fingerprint patterns in the FBI system? | Plain arch, tented arch, ulnar loop, radial loop, double loop, plain whorl, central pocket loop, accidental |
| What are inked fingerprint impressions? | Prints made by rolling fingers to show the entire friction surface |
| What are palm prints? | Prints made by the whole hand, often found at crime scenes |
| What are major case prints? | Complete hand prints, including all parts of the hand |
| What are latent prints? | Prints left by sweat, oil, or other substances on surfaces, often needing special techniques to be seen |
| What are indented prints? | Prints that are pressed into a surface |
| How are latent prints developed? | Using powders, chemicals, and lighting techniques |
| What types of powders are used to develop fingerprints? | Regular, magnetic, and fluorescent powders |
| What is Small Particle Reagent (SPR)? | A physical technique using small black particles to reveal fingerprint residues on various surfaces |
| What is Ninhydrin used for? | Developing latent prints on porous surfaces by reacting with amino acids |
| What is DFO? | A ninhydrin analogue that develops more prints than ninhydrin alone |
| What is Sticky Side Powder? | A chemical method used to develop prints on adhesive surfaces |
| What is Iodine Fuming? | A technique using iodine fumes to develop prints, especially on greasy surfaces |
| What is Cyanoacrylate Fuming? | A method where super glue fumes react with latent prints, making them visible |
| What are some mechanical methods for detecting latent prints? | Electrostatic detection, X-ray detection, and vacuum metal deposition |
| What is the sequence for processing smooth surfaces? | Visual examination, UV light, non-magnetic powder, magnetic powder, fluorescent dye staining |
| What is the sequence for processing porous surfaces? | Visual examination, fluorescent examination, iodine fuming, magnetic powder, DFO, ninhydrin, PD |
| What is a firearm? | A firearm is any weapon that uses gunpowder or other explosive materials to launch a projectile |
| What are the basic parts of a firearm? | Barrel, trigger, action, stock, and magazine |
| What are the different types of firearms? | Handguns, rifles, and shotguns |
| What is a handgun? | A firearm designed to be fired with one hand |
| What is a rifle? | A firearm with a long barrel designed to be fired from the shoulder |
| What is a shotgun? | A firearm designed to fire a spread of shot or a single projectile |
| What is the difference between semi-automatic and fully automatic firearms? | Semi-automatic fires one round per trigger pull, while fully automatic fires continuously when the trigger is held |
| What is gunpowder? | A mixture of chemicals, including potassium nitrate, sulfur, and charcoal, used as a propellant |
| What is recoil? | The backward movement of a firearm when it is discharged |
| What is the purpose of a safety on a firearm? | The safety prevents the firearm from firing accidentally |
| What is muzzle velocity? | The speed at which a bullet leaves the barrel of a firearm |
| What is a silencer or suppressor? | A device attached to the muzzle to reduce noise and muzzle flash when firing |
| What is the difference between a bullet and a cartridge? | A bullet is the projectile, while a cartridge includes the bullet, casing, gunpowder, and primer |
| What is the role of the primer in a cartridge? | The primer ignites the gunpowder, initiating the combustion that propels the bullet |
| What is a rifled barrel? | A barrel with spiral grooves that spin the bullet, improving accuracy |
| What are the basic safety rules for handling firearms? | Treat every firearm as loaded, never point at anything not meant to be destroyed, keep your finger off the trigger, and be sure of your target and what's beyond it |
| How are firearms and toolmarks similar? | Both involve the comparison of marks on metal and may require casts of impressions to be made |
| What materials are used to make casts of toolmarks? | Clay dam, epoxy, or plastic casting material |
| What do toolmarks result from? | Contact between a tool and another surface |
| What are class characteristics of toolmarks? | Shape and dimensions of the tool’s working surface, such as the distance between the teeth of a saw |
| What are individual characteristics of toolmarks? | Features produced during manufacture or resulting from wear and tear |
| What are the three types of toolmarks? | Compression (indented) toolmarks, sliding toolmarks, and cutting toolmarks |
| How are compression toolmarks made? | A tool is pressed into a softer material, showing the outline of the working surface of the tool |
| What are sliding toolmarks? | Marks created when a tool slides along a surface, typically with parallel striations |
| What are cutting toolmarks? | A combination of compression and sliding toolmarks, where the tool indents and slides over the material being cut |
| What surfaces produce better toolmark impressions? | Softer, smoother surfaces |
| What surfaces are poor for toolmark retention? | Raw wood and hard metal |
| How should toolmarks be processed at a crime scene? | Documented with notes, sketches, and photographs, and items should be collected or cast if they cannot be transported |
| How do examiners compare toolmarks? | They make test toolmarks with the submitted tool and compare them microscopically to the crime scene marks, focusing on class and individual characteristics |
| What can toolmarks on manufactured items reveal? | Information about the lot number, location of manufacture, or sale, such as hammer marks on nails or machine marks on metal shavings |
| What is a positive identification in toolmark analysis? | The class and individual characteristics match, making it highly unlikely another tool made the mark |
| What is a negative identification in toolmark analysis? | The toolmark does not match the submitted tool, and no microscopic comparison is necessary |
| What does inconclusive mean in toolmark analysis? | Class characteristics match, but individual characteristics are insufficient to confirm a match |
| What challenges do firearm and toolmark examinations face? | They are under scrutiny for subjectivity, though courts have ruled that subjectivity doesn't render them unscientific |
| What are preliminary tests in toxicology? | They are rapid, simple tests used for drug or toxicology identification, often using color changes in reaction with reagents |
| What are the advantages of color tests in toxicology? | They are rapid, require minimal sample, minimal training, and no sophisticated equipment |
| What can a negative result in a color test indicate? | It may rule out a specific drug or intoxication |
| What substances can be used for drug color tests? | Dry samples, aqueous solutions, solvent extracts, and chromatography |
| What is Dragendorff’s Reagent used for? | It identifies alkaloidal bases and amines, producing an orange to brown color |
| What does Duquenois Reagent identify? | It is used for marijuana, hashish, and THC, producing a gray to violet-blue color |
| What can affect the stability of a drug sample? | Excipients, diluents, and cutting agents can change surface pH or react with the drug |
| What is the key feature to identify marijuana microscopically? | The presence of glandular trichomes containing cannabis oil |
| What are the three types of hairs found on cannabis plants? | Covering hairs, cystolithic hairs, and glandular hairs |
| What is the microcrystal test used for? | It identifies chemical substances by observing crystal formation using a polarizing microscope |
| What is the difference between direct and indirect microcrystal tests? | Direct tests produce crystals directly from the test substance, while indirect tests involve reagent reactions or failures to react |
| What are common reagents used in microcrystal tests? | Acid, salt, or base solutions that precipitate alkaloids and other compounds |
| What are the advantages of microcrystal tests? | They are sensitive, selective, rapid, and conserve evidence |
| What are the disadvantages of microcrystal tests? | Impurities in samples can cause misleading results, and they require significant training and experience |
| How are microcrystals examined? | Through polarized light microscopy to observe size, form, and color of crystals |
| What factors can distort the crystal form in microcrystal testing? | Changes in temperature, humidity, reagent concentration, and test substance concentration |
| What is the principle behind immunoassays? | Immunoassays work on the competition between a drug (analyte) and a labeled drug or antibody specific for the drug of interest |
| What are the two main characteristics that immunoassays need to exhibit? | Specificity and sensitivity |
| What are the main components of immunoassays? | Antibodies, antigens, molecular labels, and substrate molecules |
| What is the principle of a competitive binding assay? | In a competitive binding assay, the proportion of labeled drug bound to the antibody is inversely proportional to the concentration of the unlabeled drug in the sample |
| What are UV-Visible Spectrophotometry used for? | UV-Visible Spectrophotometry is used for quantifying and characterizing drugs, diluents, metabolites, and other substances by measuring their absorption of electromagnetic radiation |
| How does Infrared Spectrophotometry work? | Infrared Spectrophotometry measures the absorption of infrared radiation by molecules, causing transitions between rotational and vibrational energy levels |
| What is chromatography? | Chromatography is a technique used to separate chemical compounds or analytes |
| What is the basic principle of Gas Chromatography (GC)? | In GC, analytes are separated based on their partitioning between an inert gas (mobile phase) and a liquid stationary phase, with different compounds having different retention times |
| What is High-Performance Liquid Chromatography (HPLC)? | HPLC separates chemical components by injecting a small sample onto a column, where the components are detected and quantified |
| How does Mass Spectrometry (MS) work? | Mass Spectrometry analyzes ions formed by bombarding a sample with electrons and measures their mass-to-charge ratio, providing a characteristic spectrum for compound identification |
| How are drugs identified in forensic toxicology? | Drugs are identified by verifying packaging, chain of custody, weighing the sample, and performing confirmatory tests like IR or GC-MS |
| What is the role of the confirmatory test in drug analysis? | Confirmatory tests, like IR and GC-MS, are used to definitively identify a drug by proving its structure |
| What are some common drugs found in forensic toxicology? | Cocaine, heroin, and marijuana |
| How is cocaine usually found? | Cocaine is found as cocaine HCl (powder) or crack cocaine (free base) |
| How is heroin commonly used? | Heroin is used as a white/brown powder or black tar, and is often injected or smoked |
| What is marijuana typically tested with? | Marijuana is tested using microscopy, color tests, and thin layer chromatography |
| How are bodily fluids typically examined in forensic toxicology? | Bodily fluids are examined by noting the weight/volume, checking for tampering, and screening with immunoassays before confirmatory testing like GC-MS |
| What are biological stains? | Originate from biological fluids and provide an indication of the nature of a stain through rapid chemical color tests |
| What is a presumptive test? | It provides an indication of a stain's nature but cannot positively identify it, requiring further confirmatory tests |
| What are the components of blood? | Red blood cells (RBCs), white blood cells (leukocytes), platelets, plasma, and serum proteins |
| How does blood clot? | Blood clots when the dissolved protein fibrinogen is converted into fibrin |
| What is the role of red blood cells? | They oxygenate tissues by transporting oxygen through the oxygen-hemoglobin complex |
| What are white blood cells responsible for? | White blood cells are involved in the body’s response to infection, with lymphocytes responsible for antibody production |
| What is plasma? | The cell-free fraction of blood containing proteins, salts, glucose, hormones, and vitamins |
| What does the physical nature of bloodstains indicate? | It can provide useful information about the nature and movement of blood at a crime scene |
| What is a common color test for blood? | The Kastle-Meyer test, which turns pink when it reacts with blood |
| What does luminol cause when it reacts with blood? | It causes stains to luminesce (fluoresce) |
| What is the Kastle-Meyer test used for? | To detect blood using phenolphthalein, hydrogen peroxide, and alcohol |
| How does the Takayama or hemochromogen test confirm blood? | It reacts with ferrous iron hemoglobin to produce red feathery crystals observable under a microscope |
| What are some confirmatory tests for blood? | Microscopic analysis and spectroscopy, which can identify hemoglobin derivatives like methemoglobin |
| What does the Hematrace test detect? | The presence of human hemoglobin in a sample, similar to a pregnancy test |
| What are the components of semen? | Spermatozoa and seminal plasma, which contains proteins, salts, and organic substances |
| What does seminal plasma contain? | Flavins (which cause UV fluorescence), choline, and proteins from the seminal vesicles and prostate |
| How can semen be visually detected? | Semen forms a white or yellow stain and may require alternative light sources to be visible |
| What does the acid phosphatase (AP) test indicate? | It indicates the presence of semen, as it reacts with sodium alpha-naphthyl phosphate and Fast Blue B to form a purple color |
| What does the PSA test detect? | Prostate-specific antigen (PSA), a protein found in high concentration in human semen |
| What is the purpose of the Christmas tree stain in semen analysis? | To stain sperm, with Nuclear Fast Red for the head and picric acid for the tail |
| What is the TSI interval used for? | To estimate how long sperm has been present in the vagina, aiding in distinguishing between assault and consensual intercourse |
| How does saliva appear when dried? | It leaves a faint trace that can be detected under alternative light sources |
| How is saliva detected? | Using a reagent like amylose-procion red on blotting paper, which changes color in contact with saliva |
| What is the main component of urine? | Urea and creatinine, with a distinctive ammonia-like odor |
| How is urine detected? | Using the Urea litmus paper test, which reacts with ammonia to change color |
| What does the Jaffe test detect in urine? | Creatinine, a breakdown product of creatine, which forms a red compound with picric acid |
| What does feces contain? | Unabsorbed residues, food residues, gut wall debris, digestive secretions, and bile pigment breakdown products |
| What does the Edelman test detect in feces? | Urobilinogen, a bile pigment, which reacts with mercuric chloride to form a pink-red product |
| How is feces analyzed microscopically? | By identifying undigested food residues and potential parasitic organisms |
Created by:
KitCaitlyn113
Popular Science sets