Many people who oppose capital punishment are the same people who support assisted suicide. A stock objection to capital punishment is the risk of executing the innocent. If you're wrong, they don't get a second chance.
But when it comes to assisted suicide, you know that you're killing the innocent. They weren't even convicted of a serious felony.
Moreover, they don't get to change their minds about the wisdom of committing suicide once they're dead. Death has a certain…you know…permanence.
If they hadn't undergone voluntary euthanasia, they might have overcome their depression, been in a much more upbeat mood a month later or a year later or whatever. But by assisting their demise, you rob them of a second chance.
Why do people who support assisted suicide but oppose capital punishment think convicted killers are entitled to the benefit of the doubt, but not depressed patients?