Learning Labs:   Molecular Biology

The story of the Chicago Heights Four

The Eighteen Year Fight
to Save Four Innocent Men

DNA HOLDS THE KEY
A Promise of Justice - The Eighteen Year Fight to Save Four Innocent Men is the story of four young African American men from suburban Chicago. Boyhood friends with no history of violence, they were arrested for, and later convicted of, a brutal interracial kidnapping, rape, and double murder they did not commit. Known as the Chicago Heights Four, they collectively spent 65 years behind bars, 18 of those years on Death Row. In a classic case of "rush to justice", the men were convicted in 1978 in trials marred by police and prosecutorial misconduct, perjured testimony, false forensic tests, and inept defense lawyers.

Authors David Protess (Professor of Journalism at Northwestern's Medill School of Journalism) and Rob Warden, (former editor of the magazine Chicago Lawyer) came to believe in their innocence and enlisted a group of journalism students, a private investigator, a Chicago Tribune columnist, and a team of volunteer lawyers to investigate the case. A key element in the investigation was the DNA evidence.

The book describes the policy decisions and the social, political, and legal forces that contributed to their wrongful conviction.

DNA FINGERPRINTING: A PROMISE OF JUSTICE
The system of DNA identification used by the FBI requires polymerase chain reaction (PCR) amplification of areas of human DNA in which a short 4-base long sequence is repeated over and over. Such sequences are called short tandem repeats or STRs. The FBI has named this system CODIS for Combined DNA Index System. The CODIS system of personal identification uses 13 STR loci in the human genome.An excellent overview of this system is found at www.cstl.nist.gov/biotech/strbase/intro.htm. Details available on this web site include the primer sequences for all 13 CODIS STR sites.

This learning lab includes a simulation of the DNA electrophoresis that would be used to classify a pair of STR loci from crime scene and suspect DNA.

BIOINFORMATICS AND HUMAN GENOME DATABASES
As part of the class visit, we also introduce students to bioinformatics and "in silico PCR" - a way of probing online GenBank sequences using the primers for CODIS loci.

Molecular Biology Labs at ScienceWorks for ME provide hands-on experience with DNA fingerprinting.

Links about DNA fingerprinting

About DNA fingerprinting from the DNA Learning Center

DNA Forensics from the Human Genome Project Information page

Additional information

Web site at Ohio University discussing the pros and cons of the death penalty