Theory 082/Law & Forensic Science
Mixtures Fail at a Ratio
The claim
DNA mixture interpretation becomes unreliable when the ratio of minor to major contributor falls below a threshold, independent of total template.
01The mechanism
Below the threshold, the minor component's alleles overlap stochastically with the major's, and the likelihood ratio can no longer separate hypotheses.
02Predictions
- P1Reliability should collapse at a contribution ratio.
- P2Increasing template alone should not fix it.
03Refutation
Reliability tracking total template would remove the ratio.