There was a huge media debate in Hamburg at the time of the trial. If I recollect correctly the court said that
a) Parches responsibility was hugely diminished due to his delusional state
b) that state had since been successfully treated so he wasn’t a danger to anyone anymore
The sentence certainly didn’t imply that the assault wasn’t a serious crime.
I have nothing to add (as usual). I just wanted to say that as I scanned the board, I thought this thread was titled “Ask the guy who stabbed Monica Seles.”