This kind of story is more John’s bag than mine, but it seems pretty glaring to me:
In Illinois, prosecutors have opposed a DNA test for Johnnie Lee Savory, convicted of committing a double murder when he was 14, on the grounds that a jury was convinced of his guilt without DNA and that the 175 convicts already exonerated by DNA were “statistically insignificant.”
In the case of Robert Conway, a mentally incapacitated man convicted of stabbing a shopkeeper to death in 1986 in Pennsylvania, prosecutors have objected that DNA tests on evidence from the scene would not be enough to prove his innocence.
And in Tennessee, prosecutors withdrew their consent to DNA testing for Rudolph Powers, convicted of a 1980 rape, because the victim had an unidentified consensual sex partner shortly before the attack.[…..]
But the prosecutors also seem to believe that Mr. Reed’s arguments are far-fetched. “There are simply too many ‘ifs’ in this case,” Mr. Moore wrote in a recent appeal.
Prosecutors said much the same when Douglas Warney, convicted of murder in Rochester in 1997, argued that a DNA test could lead to the real killer. They called his assertion “a drawn-out kind of sequence of if, if, if.” Yet that is exactly what happened after Mr. Warney’s DNA test, and the killer, when he was identified, confessed.
The article does describe some issues with using DNA evidence for crimes with multiple perpetrators but other than that, the arguments against testing seem totally bogus. (And the arguments in the multiple defendant cases aren’t that strong either.)