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Principles of Forensic DNA for Officers of the Court

Statistical Calculations

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Once a DNA match is observed, forensic scientists estimate the chance of finding that DNA profile in particular human populations. This calculation is necessary to inform the jury of the rarity of the profile.

Individuals can often be distinguished from one another at even a single locus because 8-20 alleles have been observed in representative populations at each of the 20 CODIS loci.

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