even if sentenced
Assuming 300M people in the US are innocent people, or at least innocent of a capital crime, sentencing 0.025% of innocent people to death would execute 75000 people. That's about 1000x the current rate of executions, so I think it would be worse than current efforts.
Unless you meant that 0.025% of people sentenced to death being innocent would be better then current efforts. That one's probably true.