It is one thing to argue about the basic morality of capital punishment. But there should be no controversy about putting to death people so mentally ill they did not understand that murder is wrong.

Ohio legislators are considering a bill that would amend capital punishment statutes. It would ban the death penality for people who were suffering from “serious mental illness” when they committed murder.

The law already permits trials to conclude with verdicts of “not guilty by reason of insanity.” It also protects those considered “incompetent to stand trial.” The new proposal would add additional layers, designed to ban execution for those who, at the time they killed, suffered from conditions that “significantly impaired” their ability to think rationally.

Care must be taken not to give free passes to murderers who knew they were committing serious crimes, of course. But if that can be done, lawmakers should give the bill serious consideration — in the interest of justice.