Criminal Investigations Part Two

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Part two of an introduction to criminal investigations.

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Criminal Investigations Part Two

  1. 1. Law Enforcement Criminal Investigations Part II
  2. 2. DNA Basics <ul><li>Transfer theory demonstrates that wherever we are – we leave behind evidence we where there! </li></ul><ul><li>Perhaps our fingerprints; or, </li></ul><ul><li>Our bodies are constantly shedding cells, releasing vapor containing cells and shedding hair – we leave it everywhere </li></ul>
  3. 3. DNA Basics (smaller and smaller) <ul><li>Our bodies contain 100 trillion cells. </li></ul><ul><li>Most cells contain a center piece called a nucleus. </li></ul><ul><li>The nuclei of our cells contain 23 pairs of chromosomes which are the biological instructions of who we are </li></ul><ul><li>During conception our parents contribute one half of each pair. </li></ul>
  4. 4. DNA Basics (smaller and smaller) <ul><li>Inside each chromosome there are as many as a hundred thousand pair of genes – the fundamental building blocks of our hereditary traits. </li></ul><ul><li>There are many variations for genes, but really two classifications. </li></ul><ul><ul><li>General – those that identify us as humans </li></ul></ul><ul><ul><li>Specific – those that give us individual characteristics </li></ul></ul>
  5. 5. DNA Basics (smaller and smaller) <ul><li>Our genes are made up of Deoxyribonucleic Acid (DNA) </li></ul><ul><li>DNA consists of a long string of four repeating nucleotides: </li></ul><ul><ul><li>Adenine (A) </li></ul></ul><ul><ul><li>Cytosine (C) </li></ul></ul><ul><ul><li>Guanine (G) </li></ul></ul><ul><ul><li>Thymine (T) </li></ul></ul>This long string of repeating nucleotides is called a polymer
  6. 6. DNA Basics (smaller and smaller) Cells Nucleus Chromosomes Genes DNA
  7. 7. DNA Basics (smaller and smaller) <ul><li>The order of the four nucleotides (A, C, G, T) within the polymer determine the information contained therein. </li></ul><ul><ul><li>Different order – different information </li></ul></ul>
  8. 8. DNA Basics <ul><li>A complete DNA molecule has to polymer strands with four bases – it is a tightly woven, double helix, with 3.3 billion pairs of nucleotides </li></ul>Base Pairs
  9. 9. DNA Basics <ul><li>DNA, like digital information has beginning codes and ending codes – to tell us where “packets of genetic data” or segments begin and end. </li></ul><ul><li>With DNA, at the end and beginning of DNA stands are A/T and G/C </li></ul>
  10. 10. DNA Basics <ul><li>Most of our DNA is exactly the same, only a small percentage is different from each other. </li></ul><ul><li>The location where specific DNA information is located is called a locus. </li></ul><ul><li>The information that is different between individuals is called Polymorphisms – the part examined during forensic DNA analysis. </li></ul>
  11. 11. DNA Basics <ul><li>DNA analysis can compare: </li></ul><ul><ul><li>short repeating patterns and look at the variation in length – called Variable Number of Tandem Repeats (VTNR) </li></ul></ul><ul><ul><li>base pairs – called Polymerase Chain Reaction (PCR) within Polymorphisms (specific genes) </li></ul></ul>
  12. 12. DNA Basics <ul><li>Recall general and specific genes: </li></ul><ul><ul><li>General genes (DNA) are called Monomorphisms </li></ul></ul><ul><ul><li>Specific genes (DNA) are called Polymorphisms </li></ul></ul>DNA Analysis is conducted on Polymorphisms
  13. 13. DNA Databases <ul><li>Like fingerprint information, DNA information is converted to a numerical value for ease of search. </li></ul><ul><li>Combined DNA Information System (CODIS) is actually a combination of databases. </li></ul><ul><ul><li>153 Laboratories in 49 states </li></ul></ul><ul><ul><li>Actually includes three different type of databases </li></ul></ul><ul><ul><ul><li>Convicted Sex Offender, other offenders, missing persons </li></ul></ul></ul>
  14. 14. DNA Databases <ul><li>Database Concerns </li></ul><ul><li>Who is included? Convicted, arrested or suspected? It varies from state to state. </li></ul><ul><li>What about juveniles? While juvenile arrest records don’t necessarily follow a juvenile into adulthood, the DNA database does? </li></ul><ul><li>Since a portion of DNA information is familial – if your sibling or parent is in the database – so is a part of you. </li></ul><ul><li>What about research? </li></ul>
  15. 15. Software Investigative workload <ul><ul><li>Case assignment </li></ul></ul><ul><ul><li>Clue management </li></ul></ul><ul><ul><li>Witness management </li></ul></ul><ul><ul><li>Case coordination </li></ul></ul><ul><ul><li>Productivity </li></ul></ul>Screen Capture provided by Crimestar Corporation
  16. 16. Software Crime Scene Drawings <ul><li>Crime scene drawings are </li></ul><ul><li>often used as a means of </li></ul><ul><li>documenting the location </li></ul><ul><li>of evidence, assisting in </li></ul><ul><li>determining the sequence </li></ul><ul><li>of events and explaining a </li></ul><ul><li>crime to a jury. Software, </li></ul><ul><li>some very similar to drafting </li></ul><ul><li>software aids in the </li></ul><ul><li>production of two dimension </li></ul><ul><li>crime scene representations. </li></ul>Photograph provided by Robert Eplett, California Governor’s Office of Emergency Services
  17. 17. Software Link Analysis <ul><li>Link analysis software can often help in organizing the vast amount of information and evidence a complex case can produce </li></ul>Screen Capture provided by Pen-Link™
  18. 18. Digital Photography <ul><li>Digital photography is a picture stored in the language a computer can understand. It takes that information and converts it into a visual display. </li></ul><ul><ul><li>It has numerous benefits like storage and analysis. </li></ul></ul><ul><ul><li>Because it is easier to manipulate a digital image than a traditional photograph, additional software security, procedures and protocols are necessary to maintain the chain of custody </li></ul></ul>
  19. 19. High Definition Survey <ul><li>Using laser technology a three dimensional representation of a crime scene is created. </li></ul>New Information Hyperlink to more Information Photograph provided by lecia-geosystems
  20. 20. High Definition Survey New Information <ul><li>Investigators, prosecutors and juries can now return to the scene of the crime in a virtual world. </li></ul><ul><li>Reconstruction </li></ul><ul><li>Trials </li></ul><ul><li>Training </li></ul>A three dimensional representation of a seated man with a gun Photograph provided by lecia-geosystems
  21. 21. Law Enforcement Criminal Investigations Part Two Criminal Justice Degree Information www.criminaljustice-online.com

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