Term
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Definition
-The indispensable forensic science tool
-Deoxyribonucleic acid
-has two strands and contains strands |
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Term
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Definition
-as unique to individuals as fingerprints
-a Unit of heredity |
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Term
| Building blocks of DNA are.... |
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Definition
-nucleotides which are made up of 5 carbon dioxyribo sugar
-PO4
-nitrogenus base |
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Term
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Definition
-Adenine-Thymine
-Guananine-Cytosine
^This is known as base pairing. The order of the bases is what distinguishes different DNA strands. |
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Term
| Humans have_____chromosomes in each cell. |
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Definition
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Term
| The sequence of the nitrogenus bases..... |
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Definition
| -make up the genetic code |
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Term
| Each group of three nucleotides in a DNA sequence..... |
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Definition
| -codes for a particular amino acid |
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Term
| If a nucleotide is changed for example a T is substituted for A and GAG becomes GTG..... |
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Definition
| -the wrong amino acid is placed in the protein |
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Term
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Definition
-Relies in the ability of certain chemicals, known as restriction enzymes
-The ability for us to take DNA and put it in a different strand |
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Term
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Definition
-Parts of our DNA are repeated over again, known as tandem repeats
-This helps distinguish people
-Tandem repeats act as a filler between the coding regions of DNA |
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Term
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Definition
-restriction fragment length polymorphism
-DNA that is cut from one person is different lengths than another person
-Also used for identification in a crime |
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Term
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Definition
-DNA is put in a chamber and run with electricity to separate it
-Small pieces will be at the top and large pieces will be on the bottom |
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Term
| Positive RFLP test will show that..... |
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Definition
| -the patterns on the band will match, which is admissible in courts |
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Term
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Definition
-polymerase chain reaction if there's a small piece of DNA left at the crime scene
-PCR will amplify it by millions of times
-First do PCR then do RFLP or gel electrophoresis |
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Term
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Definition
| -amplify small quantities especially in adverse conditions |
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Term
| Short Tandem Repeats(STR) |
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Definition
-short sequences that repeat themselves with in the molecule
-Great for identification |
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Term
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Definition
-combined DNA index system, standard database
-Put STR and RFLP in it |
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Term
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Definition
-used for individual characterization
-located outside the cell's nucleus
-comes from the mother
-A single mitochondria contains several loops of DNA |
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Term
| Packaging Biological Evidence |
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Definition
-photographed
-clothing must be collected
-can't be put in anything airtight
-put in paper bag |
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Term
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Definition
-Chemically, fire is a type of oxidation, which is the combination of oxygen with other substances to produce new substances
-Exothermic
-Minimum temp. is determined by the materials that are used
-A fuel will achieve abreaction rate with oxygen sufficient enough to produce a flame only when it's in a gaseous state |
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Term
| A liquid can burn if..... |
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Definition
| -it has enough energy to become a gas |
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Term
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Definition
| -it's changed into a gaseous state (pryolysis) |
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Term
| Glowing combustion (smoldering) |
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Definition
| -burning at the fuel-air interface example: a cigarette |
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Term
| to initiate and sustain combustion________________is required. |
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Definition
-A fuel
-Oxygen must be available in sufficient quantity to combine with fuel
-Heat must be applied to initiate the combustion, and sufficient heat must be generated to sustain the reaction |
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Term
| The 3 mechanisms of heat transfer are..... |
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Definition
-conduction: is the movement of heat through a solid object
-radiation: is the transfer of heat energy by electromagnetic radiation
-convection: is the transfer of heat energy by the movement of molecules within a liquid or gas |
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Term
| The arson investigator needs to begin examining a fire scene for signs of arson..... |
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Definition
| -as soon as the fire has been extinguished |
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Term
| most arsons are started with..... |
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Definition
| -petroleom-based accelerants |
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Term
| When investigating an arson..... |
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Definition
-You can begin to search even before you obtain a search warrant
-1st look for where the fire started and then look for hairs and fibers
-fire, ash, and soot must be stored in an airtight container
-Traces of flammable liquid residues may be located with a vapor detector
-A sampling of similar but uncontaminated control specimens must be collected
-an igniter must also be collected |
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Term
| Some key signs of arson are..... |
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Definition
-streamer: connects 1 line of fire to the other
-if no streamers, it's accidental
-fire moves in an upward direction and the lowest points show the most intense characteristics of burning
-combustible liquids are RARELY entirely consumed during a fire
-if there's a greater burning on the floor it's a sign of arson |
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Term
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Definition
| -occurs when oxygen combines with a fuel to produce noticeable quantities of heat and light (flames) |
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Term
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Definition
-the 1st systematic attempt at personal ID was devised by a French police expert, Alphonose Betilllion
-the Bertillion system relied on a detailed description of the subject: Rule) length and profile photographs
-no 2 people have the same fingerprints, identical twins are ALMOST the same, but NOT quite
-Galton created a classified system capable of filing many thousands of prints in a logical and searchable sequence
-Bertillion system didn't work |
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Term
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Definition
-Fingerptints are reproduction of friction skin ridges found on the palm side of the fingers and thumbs
-a fingerprint is an individual characteristic
-fingerprints remain unchanged throughout a lifetime
-fingerprints have general ridge patterns that permit them to be systematically classified |
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Term
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Definition
-The probability of the existence of 2 identical fingerprints is extremely small
-A fingerprint is known by it's ridge characteristic, known as minutia
-There are as many as 150 minutia on a finger, but in court you only have to match 20 to 30 |
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Term
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Definition
-dermal papillae is responsible for determining the form of the print
-dermis is the inner layer of the skin |
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Term
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Definition
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Term
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Definition
| -ridge point nearest the type line divergence/a split |
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Term
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Definition
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Term
| For a fingerprint comparison..... |
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Definition
| do a side by side analysis |
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Term
| When a fingerprint is found on an object..... |
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Definition
| -it's not as clear as when it's taken in a police station |
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Term
| If the loop opens toward your..... |
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Definition
-pinkie it's called a ulnar loop
-thumb it's called a radial loop |
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Term
| If it can't be classified it's called an..... |
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Definition
| -"accidental" fingerprint: combination of all the patterns |
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Term
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Definition
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Term
| 25% of the population will have at least.....a loop and an arch (1/1 category) |
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Definition
-1 Loop
-1 Arch
(1/1 category) |
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Term
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Definition
| -database for the countries fingerprints |
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Term
| When a finger touches a surface it leaves a..... |
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Definition
| -latent print (oil, sweat, and dirt from your skin) |
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Term
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Definition
| -easy to see on a soft surface |
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Term
| Latent prints usually require..... |
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Definition
| -chemical treatment on a hard surface |
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Term
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Definition
-can be used to get fingerprints out of
something
-ninhydrin reacts chemically with trace amounts of amino acid and it shows up purple |
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Term
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Definition
-can bring out a fingerprint
-works if the powder doesn't |
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Term
| When the fingerprint is brought up..... |
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Definition
| -it will be white or gray |
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Term
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Definition
| -uses UV light to pick up a fingerprint |
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Term
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Definition
-no 2 individuals handwriting are exactly alike
-is genetically determined
-you cant change your handwriting
-some words are used consistently |
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Term
| (1)When investigating Handwriting..... |
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Definition
-any object with handwriting or print whose source or authenticity is in doubt may be referred to as a questioned document
-spacing, slant, spelling, and punctuation are looked at
-weakest type of evidence (can't be charged on this alone) |
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Term
| (1)Using a microscope for Handwriting examination..... |
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Definition
-can do photoilluminecent to see what the original text would be
-an imprint will be imbedded in the computer
-only way to get rid of imprint is to destroy the harddrive
-side by side comparison look at exemplars |
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Term
| (2)When investigating Handwriting..... |
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Definition
-handwriting points are called exemplars: the more the better
-paper is compared
-always dictate words when suspect has to write something down
-can tell make and model of computer or printer from the font
-photocopiers leave marks as do any other type of machine
-compare marks on scanner/printer to something suspect has
-when examining a document may do something to tear it like smudging a pen or eraser marks |
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Term
| (2)Using a microscope for Handwriting examination..... |
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Definition
-look for defect marks, toner and printing characteristics
-compare markings made by machine
-can alter documents: look for alterations, erasing, and obliteration
-can use microscope to see what's been erased
-can use luminescence to detect different properties in the ink (check forgery)
-use infrared radiation to see what's underneath the ink to see original ink
-infrared photography can be used to see what was written if the document was burnt
-indentations are left on a pad of paper are valuable
-composition is also good evidence |
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