No I disagree, as the data involved in matching is the result of a highly filtered process. There are many many data point's that don't support a match, as evidenced by the inability to replicate a match via any other method.
Simply using the matching data allows the filtering assumptions to go unchallenged.
If what's at issue is whether the tool selected the matches and hid the mismatches, and this can't be determined by comparing the defendant's genome against the tracable raw data that went into building the database, then the defendant's team gets to examine the software or the evidence is out. Agreed.
Defendant have the right to a thorough cross-examination. The database used, the filtering process are all relevant to the actrual likelihood of a match.
Here's where we're differing. I am claiming that, once a match is found, the quality of the match can be checked by comparing the raw data of the defendant's sample against the raw data that went into the database that was searched. Even if the data was reduced and encoded in some proprietary way to assist rapid searching and probability estimation by the proprietary tool, the match can be proven - as can the assertion that no exculpatory evidence was withheld - by providing the base data and ANY algorithm that performs the equivalent probability computation in a transparent way. If it gets the same numbers, that part of the issue is proven.
If there is some question of whether the tool used improperly obtained evidence in deciding to look at this guy's data, that would make its internals relevant. If there is some question that it may have identified other, equally good, matches and these were withheld from the defence, that might make the OPERATION of the tool relevant, without putting the workings of its innards into that category.
But IANAL. If the court says you're right on this it won't surprise me. (But their reasoning would be interesting.) Also: I won't complain if they kill database-fishing for "a wrong reason". B-)
Defendants have the right to compel testimony and other evidence to be produced if they can show it is relevant. Trade secret, patent, or copyright has no power to override constitution guarantees to due process.
Total agreement there.
Prosecutors should not be allowed pseudo-science or selective disclosure of data. In fact, knowing use of either constitute prosecutorial misconduct, [an offense] that can result in financial sanctions and or disbarment.
Total agreement there, too. (Also, IMHO: Such sanctions and/or disbarment should be invoked far more often than they are. B-) )