Simply not true that he will be walking free in 9 years time.
> A sentence of permanent detention can be imposed if there is considerable danger of repetition. Permanent detention is not subject to any timeframe. However, the court always fixes a timeframe that may not exceed 21 years. When the timeframe expires the offender may be re-assessed. If the court concludes that there is still a danger of repetition the timeframe may be extended by up to five years at a time. There is no upper limit to the number of times that the court may extend the timeframe.
It's not that hard to take a hard line stance against the death penalty and still say that mass murderers don't get to walk free.
This seems honestly like something you would read on a far-right conspiracy website about what a liberal hellhole Europe is.
Assuming you're talking about Breivik and the Utøya-massacre, that happened in 2011. And he is unlikely to ever "go free". He was sentenced to "containment" (sikring), which can extended indefinitely (and almost certainly will be).
This is not true. He was sentenced to 21 years in prison, but his prison stay can be extended, indefinitely, as long as he is deemed a danger to society.
I would be extremely surprised if Breivik walks at the end of the 21 years.
But can you come up with some standard of evidence that would be 100% accurate in all cases? Real life tends to get complicated very quickly, and there have been people that have been executed on seemingly clear-cut evidence, only to be exonerated later (Timothy Evans comes to mind). When the cost of failure is so high, it's a safer move to just avoid the risk altogether.
By a strict logical interpretation, you might consider executing yourself as you have met your own stated criterion for being eligible for execution.
The fact that you move on so deftly to the word "deserve" suggests that it's vengeance you seek.
An eye for an eye makes the whole world blind.
I already mentioned the cult-of-personality example above and you breezed over it. Gang leaders are fully capable of executing kills from jail. They have influence that extends beyond the 4 walls they're contained to. Some of them have access to a vast array of money and dangerous people who they can delegate to. They can also actively influence or harm other prisoners in jail.
Treating true psychopaths with kid gloves won't make the world a better place.
We have more than adequate technology to keep such hopeless cases from harming themselves or others.
To the extent that it is moral and justified, it does not extend to include intent to kill. To the extent intent to kill is present, it is not morally “self-defense”, though it may still be within the scope that law does not punish when the other moral elements of self-defense are present (which is, itself, right and proper despite allowing some immoral acts to go unpunished as criminal law should err on the side of nonpunishment and teasing out intent when the other elements of self-defense are present is more likely to result in the reverse error.)
States can't legislate you out of your human rights.
One day the US federal courts will notice this error that they've made and fix the glitch.
As Churchill famously said, "You can always count on Americans to do the right thing - after they've tried everything else."