Keep in mind that doing 20k tests, there are likely to be mistakes made. In the case of a false positive (or a disputed positive), that shouldn't be too much of a problem -- just run the test again, perhaps using multiple labs to check the results.
For a false negative match -- you've just missed/"cleared" the probable perpetrator. Such an error is unlikely to be caught (I'd imagine) -- on the other hand if the error rate is low (say 0.5%?) -- the chance that an error is made when testing that (presumably) one swab that is from the suspect, is pretty low, even with 20k tests.
http://www.councilforresponsiblegenetics.org/GeneWatch/GeneW...
Keep in mind that doing 20k tests, there are likely to be mistakes made. In the case of a false positive (or a disputed positive), that shouldn't be too much of a problem -- just run the test again, perhaps using multiple labs to check the results.
For a false negative match -- you've just missed/"cleared" the probable perpetrator. Such an error is unlikely to be caught (I'd imagine) -- on the other hand if the error rate is low (say 0.5%?) -- the chance that an error is made when testing that (presumably) one swab that is from the suspect, is pretty low, even with 20k tests.