A screening system can be defined as "an STR system that amplifies a limited number of genetic markers." The purpose of the screening system is to make a quick and cost-effective determination of which biological samples provide the most probative information in a large population of DNA samples. The selected samples can then undergo full profiling, including analysis of all 13 core CODIS loci. Screening can be useful any time there is a large number of samples to process. This may occur when a large volume of evidence is received from large crime scenes; when there are large-scale DNA sweeps conducted to identify a suspect in a defined area; in mass disasters for the identification of victims; and in the processing of paternity cases. The benefits of screening include a lower cost compared to megaplex kits, which provide a full profile for upload to CODIS (Combined DNA Index System). In an analysis performed by the Palm Beach Sheriff's Office (Florida), the cost of using a screening method was $10 per test compared with $17.50 for a megaplex kit. Time savings can also be achieved through shorter run times and reduced analysis time. An additional benefit from using a screening kit is that it can often provide results with degraded samples that may not yield profiles with larger megaplex systems. This is possible when the screening kit is designed to amplify amplicons smaller than 250bp. The article concludes with an outline of criteria for selecting a screening kit. 1 figure