Interrogation of short tandem repeats using fluorescent probes and melting curve analysis: A step towards rapid DNA identity screening

Current forensic DNA profiling methods rely on the analysis of samples at specialised laboratories with an average turnaround time of several days. The ability to rapidly determine a partial profile of short tandem repeats at the point-of-arrest would be of great benefit to police forces around the world, for example enabling a suspect to be rapidly included or excluded from an investigation. We have developed a homogeneous PCR method for the interrogation of STR loci utilising fluorescent oligonucleotide probes and melting curve analysis. Alleles of the D18S51, TH01 and D8S1179 loci were differentiated and identified on the basis of target length and probe melting temperature. Assay performance was evaluated by comparing melting peak data with the AmpFlSTR^® SGM Plus^® system. The method is compatible with direct analysis of unpurified buccal swab samples, enabling a partial STR profile to be generated within 1 h.     

Measurement of arch widths in a human population: relation of anticipated bite marks

The authors compared arch width measurements of diagnostic dental models obtained from dental school patients. Arch width measurements were taken in the canine area on each dental cast in an effort to assist forensic dental investigators in matching certain classes of subjects to the bites they might possibly inflict. If any canine teeth were absent, the measurements were taken using other specified adjacent teeth which the investigators felt would be interpreted as the arch width determiners in a bite mark injury. The ages of the subjects varied from 14 to 87 years. Statistical comparison of the maxillary arch width, mandibular arch width, and the mean difference between maxillary and mandibular arch width were performed. Significant differences between the arch width measurements were found to exist between several classes of subjects based on race and sex.     

A simple logical approach to questioned envelopes examination.

This case report outlines research undertaken as the result of a document examination case in which two envelopes were involved. The combination of the circumstances of the case and the results of the examination allows a simple application of a logical approach to pre-assess the probability that an envelope (or a package) potentially recovered at a suspect's home comes from the same batch (same source) as questioned envelopes. This highlights that it is useful to examine envelopes.