The polymerase chain reaction (PCR) was used to amplify the HLA DQα gene using DNA recovered from evidentiary samples. Amplified HLA DQα DNA was then typed using sequence-specific oligonucleotide probes. Slight modifications of previously published DNA extraction methods improved typing success of bloodstains and semen-containing material. Evidentiary samples, consisting of 206 known bloodstains, 26 questioned bloodstains, and 123 questioned semen-containing evidentiary materials were analyzed from 96 cases previously analyzed by restriction fragment length polymorphism (RFLP) typing in the FBI Laboratory. Of the known bloodstains, 98.5% yielded DQα typing results. Of the questioned samples, 102 of 149 (24/26 bloodstains and 78/123 semen-containing materials), or 68%, produced typing results. Of the 78 cases that were RFLP inclusions, 59 yielded interpretable DQα results and these were all inclusions. The remaining 19 cases could not be interpreted for DQα. Of the 18 RFLP exclusions, eleven were DQα exclusions, four were DQα inclusions, and three could not be interpreted for DQα. It is expected that because of the difference in discrimination potential of the two methods, some RFLP exclusions would be DQα inclusions. Some samples that failed to produce typing results may have had insufficient DNA for analysis. Employment of a human DNA quantification method in DQα casework would allow the user to more consistently use sufficient quantities of DNA for amplification. It also could provide a guide for determining if an inhibitor of PCR is present, thus suggesting the use of a procedure to improve amplification. This study provides support that the HLA DQα typing procedure is valid for typing forensic samples.

Recognizing the power of stories about heroes and villainsdoes not mean that these stories are a solid foundation for public policy (Goss, 2007).Currently, all states in the United States require some categories of convicted offenders to submit physical samples for later DNA analysis. The results of these analyses are DNA profiles available to law enforcement. One of the stated goals of legislation, cited in supporting court cases, has been to deter offenders from reoffending. State legislatures in recent years have increased dramatically the scope of offenders who are required to submit samples. Empirical work on deterrence suggests that these recent expansions are undermining the deterrence potential of these policies. That potential can be restored only by reversing the recent and planned policy expansions.

The apparent stability of DNA in forensic samples has permitted the successful application of several techniques such as polymerase chain reaction (PCR)-based and restriction fragment length polymorphisms (RFLP) analysis to forensic cases. PCR-based typing of the HLA-DQ alpha region in forensic casework has been shown to be a valid and reliable technique. This inherent stability of DNA in forensic evidence has led us to address the question of whether DNA could successfully withstand certain evidence processes such as latent fingerprint and electrostatic detection apparatus (ESDA) processing and still yield a sufficient quantity and quality of DNA for PCR HLA DQ alpha typing. Through testing done with biological material on simulated and casework envelope, stamp, and cigarette butt type evidence, it was determined that samples could be processed for specific latent fingerprint and ESDA examinations and still yield sufficient DNA for conclusive HLA DQ alpha typing results.

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