SCI 114 Midterm Review Exam Questions With Answers All Correct

Where Does Forensic Science Start? - correct answers At the scene of the crime, not at the lab What does the crime lab do? - correct answers Their goal/duty is to perform scientific analysis of the evidence and give objective/unbiased results Who Is The First Person to Arrive at a Crime Scene? - correct answers The Responding Officer; job is to properly secure the scene Crime Scene Procedure - correct answers 1. Secure and isolate the scene 2. Record the scene 3. Conduct a systematic search for evidence 4. Record and collect evidence 5. Package evidence 6. Collect standard/reference samples 7. Transport and submit evidence to the laboratory Securing the Scene Procedure - correct answers 1. Approach the scene with caution If blood or other body fluids are involved, you need to be protected against blood-borne pathogens 2. Render medical aid 3. Identify victims and/or witnesses 4. Secure the scene and the physical evidence within it 5. Notify appropriate personnel Document that contains the LOCATION of a piece of evidence at any given point and EVERY PERSON who handled the evidence - correct answers Chain of Custody (the document should have the collector's initials, location of the evidence, date of collection) 2 types of sketches and how do they differ? - correct answers Rough Sketch: done at the crime scene and is not to scale Smooth Sketch: done at the lab and is drawn to scale Rough sketch aspects - correct answers Hand drawn AT the crime scene ● Contains an accurate depiction of the dimensions of the scene and shows the location of all relevant objects ● Objects located in the sketch are measured from TWO fixed points- Triangulation method ● Assign items in a sketch a number or letter ● Use a legend below the sketch that correlates the letter/number to the item's description ● Include a compass designating North, date/time ● Not drawn to scale Smooth sketch aspects - correct answers A precise depiction of the crime scene, drawn to scale ○ Example: 1" = 1 ft ● Must reflect ALL information contained within the rough sketch in order to be admissible in court ● Done in the laboratory either by hand or computer software 2 types of evidence characteristics - correct answers Individual characteristics: A piece of evidence that is unique and can be identified to the exclusion of all others Example: DNA, fingerprints Identifying/Class characteristics: Features shared by all members of a group or class Example: footprints, fibers 2 types of evidence testing and how do they differ? - correct answers Presumptive testing: a quick screening test only performed at the crime scene-- only gives an indication and must be verified by confirmatory testing Confirmatory testing: conclusively identifies the sample(ex:blood,semen,salivia) Searching the scene - correct answers A systematic and thorough search for physical evidence; search depends on the location/size of the area, the number of evidence collectors, and the actions of the suspect(s) & and victim(s) Spiral- small space Grid- midsize space Zone or strip- large space How should the following pieces of evidence be packaged: 1. Bloody sweater 2. Fibers and hairs 3. Arson debris 4. Weapons 5. Fingerprints - correct answers 1. Paper bag 2. Paper bindle (druggist fold) or coin envelope 3. Airtight container (paint can) 4. Cardboard box 5. An envelope or paper bag What is trace evidence? - correct answers Any type of evidence that is easily transferred from one surface to another via primary or secondary transfer Examples: Hairs, fibers, glass, soil, paint chips Usually not visible to the naked eye Hair - correct answers 1. outgrowth of the skin, which is produced by follicles 2. considered as class evidence (identified, shared by many; can be individualized if DNA is attached) 3. Animals have a bigger index (thicker) than humans The 3 layers of hair - correct answers Medulla: inner layer (where you see the medulla patterns) Cortex: middle layer Cuticle: outer layer Different phases of hair growth - correct answers 1. Anagen- active growth phase 2. Catagen- the transitional phase between anagen and telogen 3. Telogen- resting phase, hair becomes a bulbous shape, falls out easily, and returns to the anagen phase If a hair was forcibly removed, what will be present on the hair? - correct answers Follicular tag (DNA can still be attached), (there won't be a follicular tag if the hair naturally shed) What are 2 methods performed to detect drugs in hair? - correct answers 100-120 hairs are removed from the scalp and can detect drugs used in over 90 days ELISA: used to determine a negative or positive result in 24 hours GC/MS: used to confirm a positive result What are the characteristics that can be determined by examining the hair microscopically? - correct answers 1. Species of origin 2. Somatic origin (either from beard, pubic, limbs,or face) 3. Racial origin 4. Common origin between a questioned and known sample 5. Whether the hair was naturally shed or forcibly removed 6. Presence of artificial treatment 7. Disease/damage Collection and packaging of hair evidence - correct answers 1. Picking (with a tweezer) 2. Taping 3.Scraping 4.Vacuuming 5.Document and photograph hairs 6.Collect control samples (various areas of the body; 25 pulled/cut hairs and 25 combed hairs) 7. Package hair in a coin envelope and druggist fold Fiber - correct answers 1. Is the smallest unit of a textile *A thread is made up of many fibers twisted together* 2. Class evidence What are the 2 general types of fibers? - correct answers 1. Filament type- long, continuous fibers (they are LESS likely to shed; examples: silk, polyester) 2. Staple type- short fibers twisted together (examples: cotton, wool, some polyester) Classification of fibers - correct answers 1. Natural fibers (derived from plant, animal, and mineral sources) 2. Man-made fibers ( more than 50% of papers are man-made; re-formed natural fibers (REGENERATE; ex: rayon, acetate) or derived from petroleum products (SYNTHETIC;nylon or acrylic )) What are the 3 types of natural fibers? - correct answers 1. Animal (ex:: wool (sheep hair), mohair, cashmere (goat hair), fur fibers (mink, rabbit, beaver, camels), silk (silkworms)) 2. Plant (ex: cotton, linen, hemp, jute) 3. Mineral ( the only naturally occurring mineral fiber is ASBESTOS; used as insulating material, fire-resistant textiles Decreased usage because its carcinogenic microscopic size is easily spread throughout the air. REPLACED by fiberglass, silica, and ceramic fiber-based materials)