One of the most powerful arguments against capital punishment is that many individuals have been revealed to be innocent while waiting on death row. The risk of killing innocent people is too great.
Our laws establish a two step process of applying punishment: first the jury determines whether evidence of a wrongful act is demonstrated to a particular burden of proof; then, the punishment assigned for that wrongful act is applied. For civil disputes, the burden of proof is generally more likely than not; for criminal prosecutions, the burden of proof is beyond a reasonable doubt. In death penalty cases, in general, the jury first determines guilt beyond a reasonable doubt; then, the jury determines whether the crimes and the offender are sufficiently despicable to warrant the penalty of death, taking into account a variety of factors.
Personally, I feel--assuming the death penalty is worthwhile in the first place--capital punishment should not be limited to the most despicable crimes; rather, death should be limited to those individuals who we are absolutely certain have committed the crimes they are accused of.
I suggest that, for death penalty cases, guilt should be determined by a beyond a reasonable doubt, but the punishment of death may be imposed only where there is "irrefutable evidence" of guilt. Such a standard would allow imposition of death penalties where the evidence of guilt is overwhelming, eliminating the risk of killing an innocent person; it will satisfy the preference of many Americans to kill the worst offenders; it would allow judges to independently and dispassionately evaluate the evidence to ensure a possibly innocent person is put to death; it will also allow plea bargains to put the offender in prison for life without the need for a costly trial. Plea bargains are also useful in some instances to gain information from the offender regarding accomplices or information regarding the location of victims.
Such a standard also might reduce the impact of conscious or unconscious racism in the application of the death penalty.