A just state regularly abrogates people's rights when they intrude upon the rights of others. By sentencing people to prison, for instance, the state takes away rights to movement, association, and property rights from convicted criminals. The right to life should be no different. When you commit certain heinous crimes, you forgo your right to life. This does not devalue life, but rather affirms the value of the innocent life taken by the criminal. Certain crimes are so heinous that the only proportionate sentence is execution. As for the executioners themselves, there are methods of execution that involve multiple executioners which might reduce the associated psychological burdens. At any rate, no one is forced to become an executioner, and people who choose to take on that role do so with full awareness of the risks involved.