Rapid advancements in forensic DNA technology has resulted in its increasing use to resolve crime cases, particularly in the detection of low-level DNA traces. This has been made possible by the increasing sensitivity...Rapid advancements in forensic DNA technology has resulted in its increasing use to resolve crime cases, particularly in the detection of low-level DNA traces. This has been made possible by the increasing sensitivity of STR typing kits. Low-template DNA analysis requires careful consideration of the derived stochastic variations that lead to heterozygote imbalance, allele drop-out and increased detection of background contamination. The relevance of the evidence and the probative value of the DNA profile are important issues in the evaluation of forensic evidence.展开更多
Due to recent improvements in forensic DNA testing kit sensitivity,there has been an increased demand in the criminal justice community to revisit past convictions or cold cases.Some of these cases have little biologi...Due to recent improvements in forensic DNA testing kit sensitivity,there has been an increased demand in the criminal justice community to revisit past convictions or cold cases.Some of these cases have little biological evidence other than touch DNA in the form of archived latent fingerprint lift cards.In this study,a previously developed optimised workflow for this sample type was tested on aged fingerprints to determine if improved short tandem repeat(STR)profiles could be obtained.Two-year-old samples processed with the optimised workflow produced an average of approximately five more STR alleles per profile over the traditional method.The optimised workflow also produced detectable alleles in samples aged out to 28 years.Of the methods tested,the optimised workflow resulted in the most informative profiles from evidence samples more representative of the forensic need.This workflow is recommended for use with archived latent fingerprint samples,regardless of the archival time.展开更多
文摘Rapid advancements in forensic DNA technology has resulted in its increasing use to resolve crime cases, particularly in the detection of low-level DNA traces. This has been made possible by the increasing sensitivity of STR typing kits. Low-template DNA analysis requires careful consideration of the derived stochastic variations that lead to heterozygote imbalance, allele drop-out and increased detection of background contamination. The relevance of the evidence and the probative value of the DNA profile are important issues in the evaluation of forensic evidence.
基金This work was supported by the Department of Forensic Science of Virgina Commonwealth University and National Institute of Justice(NIJ)Award 2014-DNBX-K013.
文摘Due to recent improvements in forensic DNA testing kit sensitivity,there has been an increased demand in the criminal justice community to revisit past convictions or cold cases.Some of these cases have little biological evidence other than touch DNA in the form of archived latent fingerprint lift cards.In this study,a previously developed optimised workflow for this sample type was tested on aged fingerprints to determine if improved short tandem repeat(STR)profiles could be obtained.Two-year-old samples processed with the optimised workflow produced an average of approximately five more STR alleles per profile over the traditional method.The optimised workflow also produced detectable alleles in samples aged out to 28 years.Of the methods tested,the optimised workflow resulted in the most informative profiles from evidence samples more representative of the forensic need.This workflow is recommended for use with archived latent fingerprint samples,regardless of the archival time.
