Since their introduction into forensics some two decades ago, DNA-based geno-typing technologies have revolutionized the science of human identification. Initially, panels of 'variable number tandem repeats' (VNTR) probes were used in Southern blot applications and represented, at the time, a quantum leap over serological testing in their ability to discriminate between individuals. The invention of the polymerase chain reaction (PCR) fostered the introduction of the much shorter hypervariable 'short tandem repeats' (STR), the major forensic DNA typing tool currently used, as well as mitochondrial DNA sequencing and, more recently, Y-STRs and single nucleotide polymorphisms (SNPs). Compared to VNTR analysis, PCR-based assays are better suited for the often-compromised nature of crime scene samples, they consume 1000-fold less sample and they reduce the sample processing time from weeks to less than 24 hours. Despite these significant advances in analytical methods, improvements in throughput have largely been offset by increased specimen collection at crime scenes and through expansion of legislated mandates for criminal offences. Although the existence of backlogs in many jurisdictions may be associated with high local crime rates, the resource-consuming, manual nature of forensic casework as it is performed in most laboratories remains a significant factor contributing
Molecular Forensics. Edited by Ralph Rapley and David Whitehouse Copyright 2007 by John Wiley & Sons, Ltd.
to the backlogs. Additional opportunities for improving processing capacity and turn-around time reside in the development of faster evidence screening tools and in the introduction of automation for liquid handling and data analysis.
The elimination of offender and casework backlogs and the timely processing of incoming submissions are necessary steps towards achieving the true potential of DNA typing technologies. No less necessary is the development of informatic tools not only to provide support for automation technologies necessary for improvements in process quality, reliability and throughput, but also to take full advantage of the information content of processed data sets. Although the resolution of many casework situations resides in direct matching of genotypes obtained from crime scene evidence and suspect(s), applications requiring more intricate data analysis have emerged in response to challenges of increasing complexity encountered in the field. Current laboratory information system (LIS) developments on the offender data banking front have largely dealt with supporting parallel processing pathways and automated data review to increase the reliability of uploaded offender genotype data. Other activities on that front aim at extending direct match capabilities to 'familial' search capabilities, as many offenders have been found to have next-of-kin already included in offender data banks. Data analysis applications are emerging on the crime scene front to assist with data interpretation of mixed profiles that often necessitate software-assisted, mathematical deconvolution for resolution. In situations where recovered human remains must be identified, significantly different approaches are required because a reference biological sample from the victim is often not available. In mass fatality incidents (MFIs), entire families often perish, making it necessary to use large-scale kinship analysis to re-construct family pedigrees from within the victim's genotypic data set. The LIS applications have been built to address these numerous complexities on the path to identification in large-scale MFIs and ongoing developments aim at providing computing capabilities for even larger scale and more complex events. Much of the LIS infrastructure used for MFIs can be leveraged into the development of Missing Persons Databasing applications as very similar complexities are encountered.
This chapter presents the developments and applications of laboratory information systems that have promoted the growth of genetic forensic identification over the last decade. First, the major DNA analytical platform used in forensics is discussed to identify areas where automation technologies can provide improvements in the platform's qualitative and quantitative performance. Next, specific implementations of computing support to different forensic applications are reviewed. Finally, conclusions are presented regarding likely future directions for the adoption of technology and development activities by forensic laboratories.
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