Forensics - Montana State University

Document Sample
Forensics - Montana State University Powered By Docstoc
					By: Kalah Butler Alan Lee Reed Anderson Alan Lee Twanria McKizzie

What we are Presenting:
History of Forensics Forensic Methods

Ethics and Human Error
Non-Human DNA Analysis

Interesting video?

http://www.youtube.com/watch?v=SlZ5bF3opQ4 or http://www.youtube.com/watch?v=vrNWFmT8SLo

Forensic Science:
Forensic science is the intersection of law and science. forensics encompasses the accepted scientific methodology and norms under which facts regarding an event, artifact, or some other physical item (such as a corps or cadaver) are to the broader notion of authentication, whereby an interest outside of a legal form exists in determining whether an object is in fact what it purports to be or is alleged as being. This type of scientific evidence can be used to condemn the guilty and exonerate the innocent, and is also used in recreating crimes.

• Photography: • Modern photography began in the 1820s with
the first permanent photographs. This invention gave a boost to the individual whose main efforts were to fight crime. •The invention of the camera made it possible to depict criminals in custody so accurately that the photographs were then used later as references, where as before the mid 1800’s hand drawn posters and verbal descriptions were used to depict an criminals image. •In the 19th century French photographer Alphonse Bertillon was the first to approach a crime scene with the systematic methods of an investigator. He'd capture images at various distances and take both ground level and overhead shots. •Photographs were and are still being used to record evidence around an crime scene that then allow forensic scientists and criminal investigators to have an reference guide for that particular crime scene.

Fingerprinting:

•Fingerprints offer an infallible means of personal identification. That is the essential explanation for their having supplanted other methods of establishing the identities of criminals reluctant to admit previous arrests. •Fingerprinting has served all governments worldwide during the past 100 years to provide accurate identification of criminals. •No two fingerprints have ever been found alike in many billions of human automated computer comparisons. • In 1823, John Evangelist Purkinje, a professor of anatomy at the University of Breslau, published his thesis discussing 9 fingerprint patterns, but he made no mention of the value of fingerprints for personal identification. • In 1892, Juan Vucetich made the first criminal fingerprint identification. He was able to identify Francis Rojas, a woman who murdered her two sons and cut her own throat in an attempt to place blame on another. Her bloody print was left on a door post, proving her identity as the murderer.

DNA Fingerprinting:
•Scientists can use DNA fingerprints to identify individuals - just like actual fingerprints.

• It is especially useful for paternity testing, and for solving crimes.
•There is enough DNA in a small blood sample to make a DNA fingerprint. • Leicester University geneticist Alec Jeffrey developed the method of DNA fingerprinting in 1985. • One of the first uses of DNA Fingerprinting in a criminal case in the United States was in November 1987. •Circuit Court in Orange County, Florida, convicted Tommy Lee Andrews of rape after DNA tests matched his DNA from a blood sample with that of semen traces found in a rape victim.

The first DNA Fingerprint

Sources:

http://science.howstuffworks.com/crime-scene-photography.htm http://www.onin.com/fp/fphistory.html

http://www.pbs.org/wgbh/pages/frontline/shows/case/revolution/wars.html Introduction to Biotechnology: Chapter 8” Thieman and Palladino

History of Forensics
By Alan Lee

Narborough Village Murders
•The first reported use of genetic fingerprinting in a criminal case. •1983 in the United Kingdom •Investigators matched a semen sample with that of a similar rape/murder case. •Police conducted first mass screening of DNA by collecting 5,500 samples from male population. •Investigators came to a dead end, however a man was overheard he had given a sample in the name of a friend. •The sample was an exact match, the suspect confessed to both crimes

The Forest Hills Rapist
•First use of DNA evidence in the United States •1987 •In 1988, Victor Lopez was tried for the sexual assault of three women •All the women said their attacker was black •However, Lopez’s blood was tested against sperm left at the scene and found to be a match. •Despite the eyewitness testimony, Lopez was found guilty

The O.J. Simpson Case

The OJ Simpson Case
•Nicole Brown Simpson and her friend Ronald Goldman were murdered at her Los Angeles home on June 12th of 1994. •The prime suspect was her ex-husband, and former NFL star, O.J. Simpson •Forty five samples were collected and it was discovered that the DNA found at the crime scene was that of O.J. Simpson •Defense attorneys attacked procedures used in collecting the DNA. •The defense alleged that contamination could have occurred; at one point one witness admitted to mislabeling a sample. •This created enough doubt in the jury’s eyes, which led to Simpson being found not guilty.

September 11th

September 11
•Nearly 3000 people died as a result of the terrorist attacks on September 11th, 2001 •Dangerous conditions at ground zero made it very difficult for forensic scientists to determine the identity of victims based on their remains. •Most remains were small bone fragments and teeth •Collection points were set up around New York City where family members could make missing person reports as well as donate items that may contain DNA of the victims. •Single Nucleotide Polymorphism analysis was used to identify victims. Out of the 3000 people who died, only about 1700 were identified.

M-FISys

M-FISys
•Mass Fatality Identification System •Software system created in the wake of September 11th attacks •First software to combine STR, mtDNA, and SNP in an integrated matter. •Can be modified to be used in other disasters or in natural disasters •Altered, and used to identify over 800 individuals in three months following the South Asian Tsunami

Work Cited
• http://www.promega.com/geneticidproc/ussymp14proc/posterpresentations/ Cash.pdf “M-FISys” “Introduction to Biotechnology: Chapter 8” Thieman and Palladino

•

Forensic Methods By: Rhys Andersen

Collecting DNA
• Sources: Blood, Bone, Hair, etc.
• Sources for successful Identification: DNA from parent, sibling, child, or items used solely by the individual such as toothbrush or comb.

http://streetknowledge.files.wordpress.com/2009/02/dna460276.jpg

http://endtimesworldnews.punt.nl/upload/feds_dna.jpg

DNA Markers
• DNA markers are know as Probes. • DNA probes are used to search out and bind to complementary DNA. • DNA markers represent most most basic for of DNA identification.

QuickTime™ and a TIFF (Un compressed) decompressor are neede d to se e this picture.

http://static.howstuffworks.com/gif/future-crime-markers.jpg

RFLP
Restriction Fragment Length Polymorphism
• Restriction enzyme used to cut DNA at specific recognition points. • DNA sample are ran through gel electrophoresis to separate fragments. • DNA probes hybridize samples so that they can bind with Complementary DNA sequences. • Different Lengths of DNA fragments are compared to source DNA. • RFLP requires large amounts of DNA samples.

QuickTime™ and a TIFF (Uncompressed) decompressor are need ed to see this picture.

http://homepage.smc.edu/HGP/images/rflp.gif

Polymerase Chain Reaction

PCR

• Requires Small amount of DNA • Utilizes Polymerase chain reactions to create millions of copies • Amplified DNA is ran through gel and separation points are compared to source DNA.
QuickTime™ an d a TIFF (Uncompressed) decompressor are need ed to see this picture .

QuickTime™ and a TIFF (Uncompressed) decompressor are neede d to see this picture.

Kary Mullis accepting the nobel prize in 1993.

homepage.smc.edu/HGP/tools.htm

http://www.bio.miami.edu/~cmallery/150/gene/c7.20.7.pcr.jpg

QuickTime™ and a TIFF (Un compressed) decompressor are neede d to se e this picture.

http://www.dna.gov/basics/analysis/pcr

STR
Short Tandem Repeat Analysis
• Heightened level of accuracy • Standard for technique used by the FBI • Analyzes 13 specific short tandem repeat regions. • Specific Polymorphs chosen for analysis their increased level of diversity. • Additionally Polymorphs chosen are non coding, and not linked to traits or phenotypes. • STR used to Develop CODIS Data base. • CODIS, as of 2004 contained 2,132,470 DNA profiles, and had led to 19,000 matches.

QuickTime™ and a TIFF (Uncompressed) decompre ssor are neede d to see this picture.

http://www.dna.gov/dna-databases/types/

Mitochondrial DNA Analysis
• Used if non recoverable nuclear DNA exists. • DNA is isolated from mitochondrial DNA or mtDNA. • mtDNA is identical between mother and daughter. • Applicable method even when all Nucleated Cellular Material has been degraded.

QuickTime™ and a TIFF (Un compressed) decompressor are neede d to se e this picture.

http://evolution.berkeley.edu/evolibrary/images/news/mitochondrialdna.gif

Y-Chromosome Analysis
• Identical between father and son. • Y chromosome is passed directly from father and son, making Y-chromosome analysis extremely accurate for identification.

QuickTime™ an d a TIFF (Uncompressed) decompressor are need ed to see this p icture .

http://www.bio.miami.edu/~cmallery/150/mendel/c7.15.X.Y.jpg

Sources:
Butler, Dr. John. Forensic DNA Typing: Biology, Technology, and Ge netics of STR Markers . Academi c Press. 200 5. DNA.gov. 17 March 2009 < http://www.d na.gov/basics/analysishistory>.

"CODIS: Combined DNA Index System." World of Forensic Science. Eds. K. Lerner and Brenda Lerner. Vol. 1. Detroit: Gale, 2005. 2 pp. 2 vols. Gale Virtual Reference Library. Gale. MSU Bozeman Library. 17 March 2009 <http://find.galegroup.com.proxybz.lib.montana.edu/ips/start.do?prodId=IPS>.

"DNA Fingerprinting." The Gale Encyclopedia of Science. Eds. Brenda Lerner and K. Lerner. Vol. 2. 4th ed. Detroit: Thomson Gale, 2008. 3 pp. 6 vols. Gale Virtual Reference Library. Gale. MSU Bozeman Library. 17 March 2009 <http://find.galegroup.com.proxybz.lib.montana.edu/ips/start.do?prodId=IPS>.

Forensics
Ethics and Human Error

Ethical Issues
• Massive DNA tests are controversial • Narborough murders: 5000 men were called upon for blood samples (this is now illegal in the US and UNK w/o due cause • Many people feel this is still an invasion of privacy

Ethical Issues cont.
• DNA-profiling databases – All states authorize computer-searchable collections of DNA, and many are registered with CODIS which is run by the FBI. • CODIS includes convicted offender’s DNA, and unidentified DNA • Some states have proposed DNA collection at birth, so, relatives can be identified This allows identification of suspects, when no suspect exists Opponents believe this profiling is invasive and is a violation of state and federal laws of unreasonable search and seizure Proponents feel these databases are secure, and because samples don’t have names attached it is ok.

• • •

Rules of Evidence:
Five Standards for Court Eligibility

• Relevancy test: allows anything thought relevant • Frye Standard: Evidence gathering technique has a general acceptance in the scientific community • Coppolino Standard: allows technique if adequate foundation can be laid, even if profession as a whole is not familiar with new method

• Marx Standard: The common sense rule. Court must understand and evaluate evidence presented • Daubert Standard: Requires pre-trial hearings for scientific evidence, and must be described in a peer-reviewed journal

Human Error

• Chain of Custody: requires collection of evidence be systematically recorded and access controlled • Morgue Tables: Often have at least three different DNA types present, making obtaining an accurate sample hard • Analysis: Technicians make errors during analysis all the time. • Sanitation @ Crime Scene: a must: Sneezing, sunlight, improper storage, and mislabeling can all destroy evidence (DNA) • DNA & Juries: DNA evidence must be presented so the jury can clearly understand the statistical validity of certain pieces of evidence. If the jury cannot understand the evidence it is usually thrown out.

Sources:
• “Introduction to Biotechnology: Chapter 8” Thieman and Palladino

Non-Human DNA Analysis/ Conclusion
By: Twanria Mckizzie

Non Human DNA Analysis
• Not every analysis is of human identity, but profiles of animals and plants has been used. • Manufactures can use DNA sequencing to help make distinctions between American and Asian Ginseng ; for quality control and protects American Ginseng products

“Paternity” of Plants
• Ancestry of Cabinet Sauvignon grapes • Wine purists believe hybrid grapes are inferior • Scientists can examine the DNA cabinet sauvignon plants • Found two other varieties : Cabernet Franc & Sauvignon Blanc • This challenged the idea that the varieties of these plants that come from cross-breeding are inherently less valuable as wine grapes.

Animal Profiling
• Evidence has been used to form genetic profiles of animals • Example Is a case in Pennsylvania • DNA fingerprinting was used to prove that a hunter had illegally killed a bear. • Authorities collected blood samples from the bear den and then compared it with samples from the check station • Because of this the DNA Analysis investigators were able to find the hunter guilty.

• Investigators can use DNA profiling regularly for wild life management. • They have been able to improve some techniques of DNA fingerprinting to prove that game has been taken against regulations.

DNA Labels & Counterfeiting
• DNA labels can prevent counterfeiting and Piracy • The labels of DNA authentication can place anything of value: expensive fine art, Sport memorabilia. • The labels can be detected by using PCR or hybridization, so authenticity is verified • Examples : • 2003 super bowl, footballs were encoded with DNA • Olympic licensed material • An inspection of merchandise vendor in Sydney revealed that 15% of merchandise sold was counterfeit, which therefore contributed to 1 million dollars of lost sales.

Sources
• “Introduction to Biotechnology: Chapter 8” Thieman and Palladino


				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:14
posted:9/27/2009
language:English
pages:41
Lingjuan Ma Lingjuan Ma
About