How do you execute someone without at least testing DNA on the weapon?
In fact, an extension is "no well defended person gets convicted," which isn't quite as ironclad, but still works pretty well in practice. This is actually a good thing. Our system was intended to make it hard to convict people.
I don't support the death penalty but I see the judge's point. Most DNA evidence isn't very useful and rarely as damning or exculpatory as people think.
Eye witness testimony is only slightly more reliable as waving purple LEDs around while chanting long words and rambling off conspiracy theories. (Which is apparently now an acceptable form of criminal investigation in the US).
I did not ask for absurd. I asked what they thought was absurd.