No, I'm making a case against capital punishment on cases where there is doubt. Not to leave the possible killers go to their homes. Huge distinction.
If there is any possibility of innocence, one should be prudent and choose an alternative form of punishment. It would be no different if someone doesn't know for sure if the unborn is a child of God yet. Why not be cautious and assume it is a human child? Preserve life.
If got rid of capital punishment
Worst case scenario, the person was really a killer but spends the rest of his life behind bars.
Best case scenario, you saved an innocent (of the crime alleged) person's life.
If you executed a person
Worst case scenario,you killed an innocent (of the crime alleged) person.Best case scenario, you killed the right man.