1. By Mason, Sage, and Tucker

3. All of the people previously featured were convicted of heinous felonies including homicide and rape.
They all spent at least a decade in prison before they were exonerated by new DNA technology.
They were all sentenced to life, and in some cases multiple life sentences or death row. They were all convicted by false eyewitness, faulty DNA evidence, or coerced confession.

6. About How Long Has Forensics Existed as a Science?
50 Years
100 Years
200 Years
500 Years
1000 Years
Since Dinosaurs Roamed the Earth.

7. About How Long Has Forensics Existed as a Science?
50 Years
100 Years
200 Years
500 Years
1000 Years
Since Dinosaurs Roamed the Earth.

8. 1800s Brief Forensic History
First Use of Toxicology Testing for Arsenic
1800s
First Bullet Comparison To Capture a Murderer
First use of Handwriting Documentation in Court
First Use of Chemical Tests for the Presence of Blood
First use of Fingerprints to Catch a Criminal

9. 1900s DNA Testing Did not Become Popular Until the 1980s.
Brief Forensic History
DNA Testing Did not Become Popular Until the 1980s.
First Use of Voice Analysis
Development of the Chemiluminescent Reagent Luminol as a Presumptive Test for Blood
Breathalyzers!
1900s
First Use of Head-Space Analysis to solve an Arson Case

10. Project Innocence

11. Project Innocence

12. Project Innocence

13. Project Innocence

14. In March 1984, Dennis Maher was convicted of the assault and rape of two women in Lowell, Massachusetts.
In April 1984, Dennis Maher was found guilty of the rape and assault of a third woman.
Dennis Maher was sentenced to life without parole. He was detained in the Bridgewater State Hospital.

15. He Was Innocent
After serving 19 years in prison, Dennis was exonerated in 2003 when semen samples taken from the original crime scene were used to exclude him from the list of possible suspects.

16. How Does DNA Testing Work?
RFLP (Restriction Fragment Length Polymorphism)
PCR (Polymerase Chain Reaction)
STR (Short Tandem Repeat) Analysis
Mitochondrial DNA Analysis
DNA Profiling (Fingerprinting)

17. RFLP (Restriction Fragment Length Polymorphism)
Refers to a difference in two or more samples of homologous DNA molecules arising from differing locations of restriction sites, and to a technique by which these segments are distinguished.
Analysis technique was cheap enough to enjoy widespread application.
Played an integral role in the progression DNA forensics, however, in several court cases the admissibility of RFLP evidence was questioned.
Less prone to error than PCR, but has been largely replaced by PCR because PCR testing is faster.

18. RFLP Technique DNA cut into fragments using an enzyme.
Cut DNA is put on a Gel material.
Electrical current is applied to the Gel.
DNA is negatively charged and fragments move towards the positively charged side.
Smaller fragments move faster, and there is a separation of fragment length.

19. RFLP Technique

20. STR (Short Tandem Repeat) Analysis
Used to compare loci on DNA from two or more samples.
Consists of a microsatellite of a unit of two to thirteen nucleotides repeated hundreds of times.
Measures the number of repeating units.
Unlike RFLP, STR does not cut the DNA, rather probes are attached at the desired regions of the DNA and PCR is used to discover the lengths of the repeats.
Very accurate, a 13- loci match in DNA has a 1:1billion likelihood.

21. The Polymerase Chain Reaction (PCR)
PCR is a way to copy a piece of DNA thousands to millions of times.
Fast and relatively easy
Creates a much larger DNA sample to work with

22. How PCR Works All reactants are mixed together in a vial.
The mixture is heated to degrees Celsius for 30 seconds.

23. How PCR Works The mixture is cooled to 55-60 degrees Celsius.
The temperature is heated again to 75 degrees Celsius

24. What’s Next? DNA must be visualized. Gel electrophoresis is used.
Negative electrical charge repels negatively charged DNA.
Smaller fragments of DNA are able to move further through the gel.

25. Genetic Fingerprint Comparison
Bands of DNA in the gel are compared to bands from each suspect.
Matching patterns of bands reveal a genetic fingerprint match

26. Mitochondrial DNA Analysis
Uses DNA taken from the mitochondria instead of the nucleus.
Can be used on old samples that may not have nuclear DNA left.
Particularly useful in missing person’s cases since a child’s Mitochondrial DNA will be identical to the parent.

27. DNA Profiling
Refers to the series of techniques used to interpret DNA information.
First used in a criminal case by Sir Alec Jeffreys
Used to convict 21 year old Colin Pitchfork of the rape and murder of two 15 year old girls.
Before Pitchfork, the primary suspect was 17 year old Richard Buckland who had learning disabilities and confessed to the murder.

28. CODIS and AFIS
Short for Combined DNA Index System and Automated Fingerprint Identification System.
Contain the DNA and fingerprint information for around 10 million convicted and suspected criminals.
DNA evidence is useless without something to compare it to.
Because of laws, acquiring DNA samples from suspects can sometimes be difficult, and just because a DNA sample is acquired from a crime scene does not mean that a match will be found.

29. References
Calandro, L., Reeder, D., & Cormier, K. (2005, January 6). Evolution of DNA Evidence for Crime Solving - A Judicial and Legislative History. Retrieved June 25, 2015, from com/articles/2005/01/evolution-dna-evidence-crime-solving-judicial-and-legislative-history
Davis, C. (2015, March 11). Polymerase Chain Reaction: PCR Facts on Test and Steps. Retrieved June 25, 2015, from
Dennis Maher - New England Innocence Project. (2011, February 8). Retrieved June 25, 2015, from
Elvidge, S. (2015, June 8). Forensic Cases: Colin Pitchfork, First Exoneration Through DNA. Retrieved June 25, 2015, from
Forensic Science History. (n.d.). Retrieved June 25, 2015, from
Kilpatrick, R. (n.d.). History of DNA profiling. Retrieved June 25, 2015, from /genetics/explained/profiling-history
Murnaghan, I. (2014, October 25). Mitochondrial DNA Analysis. Retrieved June 25, 2015, from
Riley, D. (2005, April 6). STRs . Retrieved June 25, 2015, from