DNA Evidence in the Christine Jessop Homicide Case

DNA tests conducted in 1995 ied to the exoneration of Guy Paul Morin for the 1984 sex-slaying of nine-year-old Christine Jessop. This paper provides an overview of the DNA tests conducted in the case, up to and including those that excluded Guy Paul Morin as a possible source of spermatozoa found on the deceased's under- wear. Previous attempts to derive a DNA profile for the spermatozoa were hampered by a potent inhibitor of the polymerase chain reaction (PCR). PCR inhibition was eventually overcome by pretreating the samples with thiopropyl Sepharose 6B beads and supplementing the PCR with bovine serum albumin (BSA) and additional Taq polymerase. This strategy may prove useful for other cases in which PCR amplification is inhibited.