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Forensic DNA Past, Present, Future. Kathy Sullivan Illinois State Police Joliet Forensic Science Laboratory. Case Study: Jeffrey Knight. Homicide from Kankakee County in December, 1997 A head, hands and feet were found in a garbage bag in the woods
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Forensic DNA Past, Present, Future Kathy Sullivan Illinois State Police Joliet Forensic Science Laboratory
Case Study: Jeffrey Knight • Homicide from Kankakee County in December, 1997 • A head, hands and feet were found in a garbage bag in the woods • Jeffrey Knight was suspected of killing his step mother, Marguerite, and disposing of her partially dismembered body
Case Study: Jeffrey Knight • Screening results: many blood stains found, but only some were human • DNA results: performed using DQ-alpha/Polymarker and D1S80
Case Study: Jeffrey Knight • Stains found around the barn, on a reciprocating saw and the trunk and floorboard of a car match Marguerite Knight • Random match probability is 2.1 billion Blacks, 5.4 million Hispanics and 5.3 million Whites • Jeffrey Knight was convicted and sentenced to 60 years in prison (he is eligible for parole December 2027)
Case Study: Timothy Evans • Summer of 2002 A series of night-time home invasions and sexual assaults begins in Joliet and Bolingbrook • Media names the assailant the “Nightcrawler”
Case Study: Timothy Evans • Evidence from one of the “Nightcrawler” sexual assaults is received by the lab in May 2003 • Underpants of the young victim are submitted to be tested for biological fluids (semen and saliva)
Case Study: Timothy Evans • Testing indictes saliva on the crotch lining and the stain is removed for DNA analysis
Case Study: Timothy Evans • DNA analysis yields a mixture of profiles consistent with the victim and one additional male contributor
Case Study: Timothy Evans • Minor male DNA profile is entered into the DNA Index • June 11, 2003 a match is reported to a sample from an Aurora case two years before • The matching sample is a standard from Timothy Evans
Case Study: Timothy Evans • Joliet Police Department is notified and on June 14th the suspect is arrested • Confirmatory analysis verifies the match • Random match probability of 1 in 20 billion Blacks, 1 in 310 billion Hispanics and 1 in 330 billion Whites
Case Study: Timothy Evans 15,17 15,17 19,21 X,Y 14,15 29,30 15,16 11,13 12,12 9,11
Case Study: Timothy Evans 15,17 9,11 X,Y 6,7 9,9 9,10 9,11
Case Study: Timothy Evans • Timothy Evans pleaded guilty to the charges against him and was sentenced to 50 years in prison • The DNA evidence and CODIS hit were instrumental in providing law enforcement with the link to the assailant
Advances in DNA Technologies Yield Gel = how much DNA? QuantiBlot = how much is human?
Advances in DNA Technologies Quantification Procedure Tells how much human DNA AND how much male DNA is in the sample
Advances in DNA Technologies • RFLP
Advances in DNA Technologies • RFLP • PCR: • D1S80
Advances in DNA Technologies • RFLP • PCR: • D1S80 • DQ-alpha • Polymarker
Advances in DNA Technologies • RFLP • PCR: • D1S80 • DQ-alpha • Polymarker • STRs
Advances in DNA Technologies • RFLP • PCR: • D1S80 • DQ-alpha • Polymarker • STRs • Y-STRs
Additional Technologies • Mitochondrial DNA
On the Horizon • Larger STR multiplexes
On the Horizon • Larger STR multiplexes • Automation – fluid handling systems
On the Horizon • Larger STR multiplexes • Automation – fluid handling systems • High-throughput detection systems
On the Horizon • Larger STR multiplexes • Automation – fluid handling systems • High-throughput detection systems • Accreditation
Kathy SullivanJoliet Forensic Science Lab515 E. Woodruff RoadJoliet, Illinois 60432815-740-3543 Katherine_Sullivan@isp.state.il.us Forensic DNA Past, Present, Future