Just kill them the same way they killed their victims.
Check it out:

The generations-old debate over capital punishment has shifted to Washington, where President Obama’s Justice Department has launched a national review of the death penalty.

Attorney Gen. Eric Holder’s inquiry, initiated last month following a mishandled execution in Oklahoma, is still in its early stages. The effort includes a look at state death penalty protocols, though its scope and ultimate implications are not yet clear.

But by ordering up the review, Obama is raising questions about what role, if any, the federal government should have on an issue that is traditionally the province of the states.

Some congressional Republicans are warning the administration to tread lightly.