There are lists of MANY people exonerated after execution on the Internet, look it up.
But I don’t know why DNA makes any difference. There were lots of people determined to be innocent after execution before we had DNA forensics. And many cases don’t even have DNA evidence today.
Mistakes range from lying witnesses, prosecutorial misconduct, police incompetence, eyewitness misidentification, and a host of other reasons.
https://en.wikipedia.org/wiki/List_of_wrongful_convictions_in_the_United_States
That said, I acknowledged that it happens as I said man's justice isn't perfect.
As for DNA, advances are still being made and now the smallest amount of anything can be analyzed. Again, man's justice isn't perfect but it's what we have.
Hope the rest of your night is peaceful.