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Police Technology Chapter Thirteen. Technology in Investigations. Learning Objectives. How technology has changed crime scene protection and evidence gathering Basic science of DNA Fingerprint technology Issues surrounding DNA databases Digital photography Investigative software.
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Police TechnologyChapter Thirteen Technology in Investigations Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Learning Objectives • How technology has changed crime scene protection and evidence gathering • Basic science of DNA • Fingerprint technology • Issues surrounding DNA databases • Digital photography • Investigative software Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Forensic Science The word forensic comes from the Latin – Foren. Essentially, it means to debate. In modern terms it has come to mean bringing any science into the courtroom. Any science or specialty brought into the courtroom such as: • Forensic pathology or forensic accounting Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Transfer Theory Whenever two objects come into contact they exchange evidence of that contact. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Chain of Custody • Testimony and documentation that details the location and condition of evidence from seizure to trial. • It assures the court that items entered into evidence are in the same condition as when they were seized. • The chain of custody and the procedures used to analyze evidence are more often challenged than the science behind the analysis. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Daubert Test • In order for the analysis of evidence to be used against a defendant, the court must accept the scientific conclusion as valid. • The standard for accepting scientific analysis is the Daubert Test – from Daubert v Merrel Dow Pharmaceuticals, inc. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
In the Daubert TestThe Court asks - • Is the science derived by the scientific method? • Has the science been subjected to peer review or publication? • Does the relevant scientific community generally accept the science? • What is the error rate of thee scientific technique used to gain the information? • Are there standards for controlling the technology used to obtain the scientific evidence? Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Crime Scenes • A crime scene is any location wherein evidence of a crime may be located. • For instance, a search of an offender’s home may yield evidence, but not be the location the crime occurred. • Protocols for scene protection, documentation and evidence recovery are critical at all crime scenes Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Crime Scenes • Evidence tends to deteriorate • Investigator’s often refer to the “golden hour;” the time when evidence is best recovered. • Some jurisdictions are taking the crime lab to the crime scene Photographs provided by OBS INC., Specialty Vehicles Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Fingerprint Advances • The recovery of latent (hidden) fingerprints is not longer restricted to powder: • Superglue fuming • Laser applications • Unique powders Technology has advanced to the point wherein some jurisdictions use superglue fuming wands at the crime scene Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics • Transfer theory demonstrates that wherever we are – we leave behind evidence we where there! • Perhaps our fingerprints; or, • Our bodies are constantly shedding cells, releasing vapor containing cells and shedding hair – we leave it everywhere Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics(smaller and smaller) • Our bodies contain 100 trillion cells. • Most cells contain a center piece called a nucleus. • The nuclei of our cells contain 23 pairs of chromosomes which are the biological instructions of who we are • During conception our parents contribute one half of each pair. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics(smaller and smaller) • Inside each chromosome there are as many as a hundred thousand pair of genes – the fundamental building blocks of our hereditary traits. • There are many variations for genes, but really two classifications. • General – those that identify us as humans • Specific – those that give us individual characteristics Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics(smaller and smaller) • Our genes are made up of Deoxyribonucleic Acid (DNA) • DNA consists of a long string of four repeating nucleotides: • Adenine (A) • Cytosine (C) • Guanine (G) • Thymine (T) This long string of repeating nucleotides is called a polymer Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics(smaller and smaller) Cells Nucleus Chromosomes Genes DNA Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics(smaller and smaller) • The order of the four nucleotides (A, C, G, T) within the polymer determine the information contained therein. • Different order – different information Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics • 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 Base Pairs Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics • DNA, like digital information has beginning codes and ending codes – to tell us where “packets of genetic data” or segments begin and end. • With DNA, at the end and beginning of DNA stands are A/T and G/C Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics • Most of our DNA is exactly the same, only a small percentage is different from each other. • The location where specific DNA information is located is called a locus. • The information that is different between individuals is called Polymorphisms – the part examined during forensic DNA analysis. Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics • DNA analysis can compare: • short repeating patterns and look at the variation in length – called Variable Number of Tandem Repeats (VTNR) • base pairs – called Polymerase Chain Reaction (PCR) within Polymorphisms (specific genes) Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Basics Recall general and specific genes: • General genes (DNA) are called Monomorphisms • Specific genes (DNA) are called Polymorphisms DNA Analysis is conducted on Polymorphisms Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Databases • Like fingerprint information, DNA information is converted to a numerical value for ease of search. • Combined DNA Information System (CODIS) is actually a combination of databases. • 153 Laboratories in 49 states • Actually includes three different type of databases • Convicted Sex Offender, other offenders, missing persons Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
DNA Databases Database Concerns • Who is included? Convicted, arrested or suspected? It varies from state to state. • What about juveniles? While juvenile arrest records don’t necessarily follow a juvenile into adulthood, the DNA database does? • Since a portion of DNA information is familial – if your sibling or parent is in the database – so is a part of you. • What about research? Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Software Investigative workload • Case assignment • Clue management • Witness management • Case coordination • Productivity Screen Capture provided by Crimestar Corporation Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
SoftwareCrime Scene Drawings Crime scene drawings are often used as a means of documenting the location of evidence, assisting in determining the sequence of events and explaining a crime to a jury. Software, some very similar to drafting software aids in the production of two dimension crime scene representations. Photograph provided by Robert Eplett, California Governor’s Office of Emergency Services Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
SoftwareLink Analysis • Link analysis software can often help in organizing the vast amount of information and evidence a complex case can produce Screen Capture provided by Pen-Link™ Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Digital Photography • Digital photography is a picture stored in the language a computer can understand. It takes that information and converts it into a visual display. • It has numerous benefits like storage and analysis. • 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 Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
New Information High Definition Survey • Using laser technology a three dimensional representation of a crime scene is created. Photograph provided by lecia-geosystems Hyperlink to more Information Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
New Information High Definition Survey Investigators, prosecutors and juries can now return to the scene of the crime in a virtual world. Reconstruction Trials Training A three dimensional representation of a seated man with a gun Photograph provided by lecia-geosystems Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster
Police Technology Explore Forensic Science at www.forensicprofiles.com Copyright 2005 - 2009: Hi Tech Criminal Justice, Raymond E. Foster