DNA Forensics MUPGRET Workshop. “DNA evidence…offers prosecutors important new tools for the identification and apprehension of some of the most violent.

Slides:



Advertisements
Similar presentations
Brief History of Forensic DNA Typing
Advertisements

DNA Analysis Chapter 12. General DNA Information Double helix—two coiled DNA strands Composed of nucleotides—units containing a sugar molecule (deoxyribose),
DNA Profiling (DNA fingerprinting). What is DNA Profiling? A technique used by scientists to distinguish between individuals of the same species using.
Explain how crime scene evidence is
NOTES 13.4 DNA Collection. CODIS Combined DNA Index System contains DNA profiles from convicted offenders, unsolved crime scene evidence and profiles.
DNA Fingerprinting Mark Bailey Vicki L. Burnett Walker B. Carroll.
DNA Forensics MUPGRET Workshop “DNA evidence…offers prosecutors important new tools for the identification and apprehension of some of the most violent.
Paternity Testing Biology Alliance May 13. A pair of homologous chromosomes, (one from mom, one from dad) Gene unit of DNA information about a trait.
DNA Fingerprinting Sotheavy Vann. What is DNA Fingerprinting?  “The generation of a set of distinct DNA fragments from a single DNA sample”  Aka DNA.
Crime Scene Investigation Science in Motion Cedar Crest College.
DNA Profiling (DNA fingerprinting).
explain how crime scene evidence is
1 Chapter 7 Chapter 7 DNA Fingerprinting Learning Goals: o Explain how crime scene evidence is collected and processed to obtain DNA o Describe how radioactive.
How can DNA be used to solve Crimes?
DNA & Proteins B3a.
DNA The Golden Key of Forensic Evidence. DNA Deoxyribonucleic Acid Can be taken from cellular tissue or bodily fluids – Examples: hair, bones, blood,
DNA Profiling. What is DNA? DNA stands for Deoxyribo-Nucleic Acid –A chemical found in every cell of our bodies –Carries genetic information from one.
Watson & Crick Discovered the basic shape of DNA
Dr. Carolyn Hancock Forensic DNA Profiling: An introduction to scientific principles Presentation to the Portfolio Committee of Police Criminal Law (Forensic.
DNA Fingerprinting. Also known as DNA profiling Used in criminal and legal cases since the 1980’s to determine identity or parentage Also used to identify.
Forensic Science: Fundamentals & Investigations, Chapter 7 1 Introduction and History of Biological Evidence in Forensics DNA fingerprinting or DNA profiling,
Sgt. Kevin McKinney Investigations Division Elko County Sheriff’s Office.
FORENSICS Cabanto, Ecat, Talampas, Vocal, Beleran, Mina IV-Gluon.
PCR Y.Martinez, LSHS, 2014 DIRECTIONS: COPY NOTES IN ORANGE.
Forensics (DNA Technology). What is DNA? DNA is the carrier of genetic information and provides a structural plan for proteins. It consists of linear.
Chapter 1: Forensic Biology.  Common Disciplines:  Crime scene investigation  Latent print examination  Forensic Biology  Controlled substance analysis.
All rights Reserved Cengage/NGL/South-Western © 2016.
Bio II: Forensics.  DNA molecules are found in the nucleus of cells in the human body in chromosomes.  People have 23 pairs of chromosomes, with an.
Chapter 10 Advanced Concepts in DNA © 2012 Cengage Learning. All Rights Reserved.
DNA Profiling (DNA fingerprinting)
DNA Evidence How can DNA be used to solve Crimes?.
DNA Forensics 352 – O’Dette. Why DNA? DNA is individual evidence DNA links or eliminates a suspect to a crime DNA identifies a victim even if no body.
DNA Fingerprinting Review. Why DNA? DNA is individual evidence DNA links or eliminates a suspect to a crime DNA identifies a victim even if no body is.
T ECHNIQUES OF DNA A NALYSIS Josh Maniez CJ 210 6/12/15.
DNA EVIDENCE. What is DNA? DNA stands for deoxyribonucleic acid and contains genetic information. DNA is a polymer composed of building blocks called.
Explain how crime scene evidence is
Explain how crime scene evidence is
Tuesday November 8th, 2016 Announcements Agenda ?
All rights Reserved Cengage/NGL/South-Western © 2016.
DNA Review Packet.
All rights Reserved Cengage/NGL/South-Western © 2016.
DNA Fingerprinting DNA Profiling.
DNA Profiling (DNA fingerprinting).
DNA Profiling and using electrophoresis
explain how crime scene evidence is
DNA Fingerprinting 13.3 What is DNA used for?
History of Biological Evidence in Forensics
Chapter 7 T. Trimpe DNA Analysis Chapter 7 T. Trimpe
Explain how crime scene evidence is
DNA Profiling (DNA fingerprinting).
Explain how crime scene evidence is
Forensic DNA Analysis.
DNA Profiling (DNA fingerprinting).
Aim: How is genetics used in law enforcement?
DNA Fingerprinting Ch 7 – Unit 5.
DNA Profiling (DNA fingerprinting)
DNA Fingerprinting and Forensic Analysis
DNA Profiling (DNA fingerprinting).
DNA Profiling (DNA fingerprinting).
DNA Profiling (DNA fingerprinting).
DNA Profiling(DNA fingerprinting)
The Indispensable Forensic Tool
Explain how crime scene evidence is
explain how crime scene evidence is
Structure and Function within Forensic Science
DNA Profiling (DNA fingerprinting).
Explain how crime scene evidence is
DNA Profiling (DNA fingerprinting).
Presentation transcript:

DNA Forensics MUPGRET Workshop

“DNA evidence…offers prosecutors important new tools for the identification and apprehension of some of the most violent perpetrators, particularly in cases of sexual assault. At the same time, DNA aids the search for truth by exonerating the innocent. The criminal justice system is not infallible.”Janet Reno

Biological Basis The same DNA is found in virtually all cells in our bodies. The four letters of DNA ATCG spell out instructions that give each individual their unique appearance. The arrangement of the letters is different in each individual. ~1 letter per 1000 is different.

DNA forensics Makes use of the similarities and differences in our DNA sequences to determine whether two biological samples come from the same individual or not.

VNTR Variable number of tandem repeats. Type of DNA marker that is unique to each individual. DNA of about 80 base pairs that is repeated many times in a row. Number of repeats differs between individuals = different size DNA fragments on a gel.

VNTR By comparing across multiple VNTR genes we can get a more accurate test of whether two samples are the same or not.

Probability One gene has 20 alleles. The probability that two individuals have the same allele is 1/20. If two genes each have 20 alleles and two individuals have the same alleles at both the probability is 1/20 x 1/20 = 1/400.

Probability People have two alleles for each gene. If there are 20 alleles for that gene. There are 210 possibile genotypes for that gene. The number of possible combinations at 2 genes with 20 alleles is 210 2, for 4 genes with 20 alleles is 210 4, etc.

Marker 1 Marker Related 1 & 4 2 & 3

Similar DNA Profiles Twins from a single egg have identical profiles. Siblings, parents, and other blood relatives share some alleles in common. The expected proportion depends on how closely related the pair of individuals are.

Uses of DNA Profiling Victim identification September 11 Srebrenica Massacre Missing persons Military personnel Paternity Testing

Use of DNA Profiling Criminal Testing Conviction Exoneration Excluding suspects Identifying protected species

Do matches establish guilt? Not necessarily Must have additional evidence Chain of evidence must be preserved Person may have had reasonable access to the crime scene

Advantages of DNA Evidence More sensitive than blood typing More informative More resilient

How reliable is DNA profiling? Generally, highly reliable. Reliability is affected by methods used to collect, store and analyze samples. Most common problem is contamination or mixture of a sample. Standards have been established for forensic analysis.

CODIS Convicted Offender database Contains for 44,000 DNA profiles in the forensic evidence section. Over 5 million profiles will be entered in the next 4 years. Contributed to matches in more 6000 cases.

CODIS Who should be included? Currently convicted offenders are required to be registered in the UK. CODIS rules say only convicted criminals after conviction can be entered but not all states comply with this. Some states submit only certain types of criminals.

CODIS Some states allow use for all types of crime investigations. Others only for sex-related or violent crimes.

Problems with DNA evidence Evidence can be degraded if not properly handled. Backlogs in processing (16,000 rape cases backlogged in NYC). Contamination Human error

Other questions Should tissue samples be saved or destroyed after profiling? Can personal or medical information be obtained from DNA profiles? Why are innocent people convicted of crimes and then exonerated by DNA evidence?

More questions Is it possible for an innocent person to be convicted based on DNA evidence? How has DNA evidence changed the criminal justice system?