The introduction of DNA technology into the forensic laboratory in the mid-1980s enabled laboratories to process a larger array of sample types and utilize more sophisticated tools to help answer difficult questions inherent in forensic casework.

Restriction fragment length polymorphism (RFLP) methods were supplemented by hybridization-based technologies such as the DQA1/Polymarker kits, which became the first commercially available DNA typing kits for forensic use. These methodologies had limitations that precluded their use on a wide spectrum offorensic sample types.

RFLP methods, while highly discriminating, proved to be technically challenging, required a large amount of biological material, and were very time-consuming. The hybridization-based technologies were not particularly discriminating and the ability to detect and interpret mixed DNA samples was challenging.

The adoption of short tandem repeat (STR) markers as the standard for both casework and databasing provided a number of advantages: (1) STR markers are highly discriminating and amenable to multiplexing, (2) the small size of the amplicons allow improved genetic profiling of degraded DNA, and (3) the ability to detect amplified product in a quantitative fashion using capillary elec-trophoresis and gel-based methods meant that mixtures were detectable and often interpretable.

The selection of the 13 core markers for development of the Combined DNA Indexing System (CODIS) and selection of similar marker sets for other national databases provided the means to solve no-suspect cases through searches against DNA profiles obtained from previously convicted offenders. Further advancements in the development of STR multiplexes have also facilitated the specific detection of male DNA in the presence of higher amounts of female DNA (Y-STR kits) and the recovery of probative information from severely compromised samples such as human remains (miniSTR kits).