Why is it technically impossible to get away with a crime thanks to forensic evidence?
Over the past nine weeks I have done extensive research on the topic of forensic investigation. I have studied DNA, fingerprinting, and trace evidence techniques and studies. The best response I can come up with is the follow:
CSO's (Crime Scene Officers) have a bulletproof plan of attack on crime scenes. They isolate and quarantine the area. Sweep every inch for footprints, blood, hair follicles, anything which can create a lead. They then spend hours analyzing evidence and data until they come up with solid evidence which points them to a suspect.
Though Some criminals have gotten away in the past, in todays society, that percentage is decreasing rapidly. New tools, and investigative teachings are making it harder and harder to get away. In the end though science will prevail, they will get caught, and they will go to prison. Case closed.
Sunday, May 29, 2011
Overview of Wiki
WIKI PAGE:
http://tocatchacriminal.wikispaces.com/
This wiki page will cover the following information that I have learned over the past 9 weeks of research. It will organize my studies into 3 major sub-headings, DNA, fingerprints, and tools. This Wiki will cover all the specifics of forensic investigation and analysis. I hope you enjoy it.
http://tocatchacriminal.wikispaces.com/
This wiki page will cover the following information that I have learned over the past 9 weeks of research. It will organize my studies into 3 major sub-headings, DNA, fingerprints, and tools. This Wiki will cover all the specifics of forensic investigation and analysis. I hope you enjoy it.
Friday, May 20, 2011
DNA Forensics
DNA forensics has and can be used for identification purposes. There is one distinctive issue, in DNA trace and matching only 1/10 of a percent of DNA differs from person to person, about 3 million bases. This means that only a very small part of human DNA is different from person to person. There is a chance though that two people have identical probes in different parts of there DNA. This is very slight and unlikely.
At a crime scene DNA collection can come from a variety of sources including blood, hair, skin tissue and bone. These specimens are then collected and there DNA sequence is observed. CSO's split the DNA and see which base pair in which order connect to the sequence. The order in which these pairs are arranged is different for every person. The DNA from the suspect is then collected and compared with the sample sequence. Usually one single match of a few base pairs isn't enough for prosecution, but four over five matches in different areas of the sequence may be enough.
There is a chance that another person may have contributed but the chances are very unlikely. DNA forensics has all to do with odds. When convicting an individual the odds of an eye-witnes testimony are 50:50. DNA provides better odds when prosecuting. The more probes that match, the higher the odds. In the end it all comes down to what the judge and jury accept as sufficient evidence.
Website:
, . "DNA Forensics." Human Genome Project Information. 2009. U.S. Department of Energy. 20 May, 2011. <http://www.ornl.gov/sci/techresources/Human_Genome/elsi/forensics.shtml>
At a crime scene DNA collection can come from a variety of sources including blood, hair, skin tissue and bone. These specimens are then collected and there DNA sequence is observed. CSO's split the DNA and see which base pair in which order connect to the sequence. The order in which these pairs are arranged is different for every person. The DNA from the suspect is then collected and compared with the sample sequence. Usually one single match of a few base pairs isn't enough for prosecution, but four over five matches in different areas of the sequence may be enough.
There is a chance that another person may have contributed but the chances are very unlikely. DNA forensics has all to do with odds. When convicting an individual the odds of an eye-witnes testimony are 50:50. DNA provides better odds when prosecuting. The more probes that match, the higher the odds. In the end it all comes down to what the judge and jury accept as sufficient evidence.
Website:
, . "DNA Forensics." Human Genome Project Information. 2009. U.S. Department of Energy. 20 May, 2011. <http://www.ornl.gov/sci/techresources/Human_Genome/elsi/forensics.shtml>
Friday, May 13, 2011
This video shows the basics of computer forensics, and information technology. They talk about how an independent company is hired to investigate and find the truth, "hidden in the computer." Even when you delete your browser history, or clear your cache, your computer always leaves a permanent mark of whatever you do. Sort of like a digital fingerprint. I hope you enjoy.
Film and Video:
, . "STEM Careers for Students: Volume 02". Computer Forensics Specialist . 2010. <Discovery Education: http://player.discoveryeducation.com/index.cfm?guidAssetId=E039D2D7-B001-4190-98EC-364A5E63FFE0&blnFromSearch=1&productcode=US>. 13 May, 2011.
Investigating a Crime Scene
In this video you will see how CSO's (Crime Scene Officers) investigate and collect data from a crime scene. They go over the techniques and put them in a real life situation. They show you how a crime that happened in the past would have been investigated if modern forensics techniques were used. At the end there is a question. If you choose you can answer it in the comment section.
Film and Video:
, . "Discovery Education". Scientific Investigation: Modern Forensics. 2004. <website: http://player.discoveryeducation.com/index.cfm?guidAssetId=890CCA23-7567-40E7-9766-49179E21E14B&blnFromSearch=1&productcode=US#>. 13 May, 2011.
Friday, May 6, 2011
Forensics Science Lab Setup
Each major city has a Crime lab which is dedicated to the types of problems and crimes associated with the area. For example, in a city with drug trafficking along state or international borders there is usually a Federal forensics lab which can deal with drug investigation. A typical forensics lab breaks into the following subsections, hair and fiber/trace analysis, drugs and technology, forensics photography, ballistics and firearms analysis, dental/odontology, anthropology, fingerprinting, medical examiner/coroner, questioned documents, serology/forensic biology (DNA), evidence collection teams (CSI), evidence intake and security, records and archive section, support staff.
Most labs are organized so that each section is separated from the others based on what equipment is used in what department. One of the most important things in a crime lab is the handling and passing down of evidence. From the time it comes off the crime scene, evidence must be catalogued and signed for every person that touches it. Whom ever comes into contact with evidence folders or bags has a certain responsibility to maintain the security of the evidence. Evidence tampering is a crime punishable by law, this is why evidence handling is a difficult area.
Book:
Fisher, Barry and David Fisher, Jason Kolowski. Forensics Demystified. : McGraw-Hill, 2007.
Most labs are organized so that each section is separated from the others based on what equipment is used in what department. One of the most important things in a crime lab is the handling and passing down of evidence. From the time it comes off the crime scene, evidence must be catalogued and signed for every person that touches it. Whom ever comes into contact with evidence folders or bags has a certain responsibility to maintain the security of the evidence. Evidence tampering is a crime punishable by law, this is why evidence handling is a difficult area.
Book:
Fisher, Barry and David Fisher, Jason Kolowski. Forensics Demystified. : McGraw-Hill, 2007.
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