Which statement best defines random match probability (RMP) in DNA statistics and its use in interpreting a DNA profile match?

Which statement best defines random match probability (RMP) in DNA statistics and its use in interpreting a DNA profile match?

• A. The probability that a laboratory test yields the correct result.
• B. The probability that two unrelated individuals share a DNA profile.
• C. The prior odds used in Bayesian interpretation.
• D. The probability that a randomly chosen person matches the DNA profile.

Answer: (D)

RMP describes how common a given DNA profile is in the population. It is the chance that a randomly chosen person would have exactly that profile, so a very small RMP means the profile is rare in people and a match is more informative. In practice, scientists estimate this by combining the allele frequencies across the informative loci (often assuming independence and Hardy-Weinberg equilibrium) to produce a single probability for the observed profile. This helps interpret a match: a low RMP indicates that a random person is unlikely to share the profile, strengthening the evidence that the source is the person whose DNA was found. RMP is not a measure of lab test accuracy, nor simply the probability that two unrelated individuals share a profile, nor the prior odds used in Bayesian interpretation.