Unit 7: Communication Skills

DNA Profiling

DNA (deoxyribonucleic acid) profiling is also termed DNA finger-printing because genetic material is unique to each individual and can serve as the basis for suspect identification. DNA profiling is a new investigative technology which began as a test for determining paternity. One of the first successful adaptations of the technique to criminal prosecution occurred in 1987 when 32 year-old Robert Melias was convicted of raping a 43-year-old disabled woman. The conviction came after genetic tests on the semen left on the woman’s clothes positively identified him as the perpetrator. To date, courts in 49 states have admitted DNA evidence in 417 trials and hearings. Although the U.S. Supreme Court has yet to address the acceptability of DNA profiling in criminal prosecutions, the U.S. Court of Appeals for the Second Circuit ruled in 1992 in Us. v. Jakobetz that DNA tests results are admissible in federal criminal trials.

DNA profiling requires only a few human cells for comparison purposes. One drop of blood, a few hairs, a small amount of skin, or a trace of semen usually provide sufficient genetic material for comparison purposes. Because the DNA molecule is very stable, genetic tests can be conducted on evidence taken from crime scenes long after latent fingerprint have disappeared.

A number of private firms are moving into the area and offering DNA comparisons to enforcement departments on a fee-paid basis. Such firms provide customized reports comparisons with a tum around time from four to eight weeks, and usually offer the services of expert witnesses. Experts on the cutting edge of the new technology already have plans to develop a computerized DNA data base, where a person’s genetic structure could be digitized, stored, and searched for as fingerprints are today.