NCJ Number
129126
Journal
Criminal Law Bulletin Volume: 27 Issue: 2 Dated: (March-April 1991) Pages: 114-133
Date Published
1991
Length
20 pages
Annotation
Although DNA fingerprinting has received widespread attention and many believe it will revolutionize law enforcement, there are several inherent imprecisions in the laboratory processes used at Lifecodes, Inc., a specialist in DNA testing, that can diminish the test's reliability and admissibility as evidence.
Abstract
Lifecodes uses a process called restriction fragment length polymorphism which breaks the DNA into small fragments at specific points and measures each fragment; identification of same-length fragments in two samples is strong evidence that they came from a common source. However, there are many areas of potential error or inaccuracy in each of the seven steps of the process: extraction of DNA, restriction digestion, gel electrophoresis, Southern transfer, hybridization, autoradiography, and interpretation of the DNA print. Further areas for inaccuracy lie in the probability calculation which must rely on band measurements and frequencies. The author suggests that courts should allow Lifecodes to testify about a defendant's DNA print and its match to a crime scene sample, but not admit evidence about the probability of a random match. 87 notes (Author abstract modified)