ABSTRACT
DNA databasing, the search for missing persons, family lineage studies, identication of human remains, mass disasters, relationship testing, and so forth. e predominant genotyping method currently practiced is proling for short tandem repeat (STR) loci. STRs are microsatellite loci that reside as repeat units of nucleotide sequence typically ranging from two to six nucleotides (Butler 2005; Edwards et al. 1991; Moretti et al. 2001). Polymorphic STR loci-that is, loci exhibiting variation in the number of repeat units among individuals-are useful in distinguishing between two individuals. Forensic DNA analysis is probably the fastest-growing area of crime investigation in the past two decades since the rst report of the ability to detect many highly variable genetic loci simultaneously by Jereys et al. (1985). e success of DNA proling in resolving crime can be gauged from the survey by the International Criminal Police Organization (INTERPOL) in 2008 comprising 172 member countries (INTERPOL 2009). Based on this survey, the number of countries utilizing DNA proling for forensic casework increased from 53 in 1999 to 120 in 2009, and the number of countries adopting a national DNA database increased from 16 to 54. DNA databases in the United Kingdom, United States, and China, established in 1995, 1998, and 2001, respectively, are presently the largest DNA databases. e demand for DNA proling is increasing for a variety of reasons, including acceptance of DNA results by court systems, legislation passed by governing bodies, increased funding, the generation of DNA databases, success in resolving cases worldwide, increasing awareness, expanding the scope to resolving property crimes, inow of cold cases, postconviction testing, and advancements in DNA analysis technologies. e number of samples from convicted oenders and arrestees combined increased substantially, which is evident from the data published by dierent agencies (Federal Bureau of Investigation 2012; National Policing Improvement Agency: Statistics 2012; National Policing Improvement Agency: e National DNA Database 2012; Nelson 2011). e end result is increased backlogs in spite of the expansion of sample-processing capabilities of the forensic laboratories.
