So, you'd rather they go to prison, not learn how to be valuable members of society and how to be better, and just end up in prison again for something later? Yeah they did something despicable, but people often seem more interested in punishing criminals than rehabilitation. In countries where rehabilitation of criminals is the focus, crime recurs much less, because the goal isn't to punish as harshly as possible and instead to rehabilitate the criminals so they never do it again.

Punishing out of principal is all great but ultimately, the only people who are hurt by tons of people being in jail and unproductive, potentially for their whole lives, since some countries focused on punishment frequently make it very hard to find good work after a criminal gets out.

In no way do I approve of what was done here, or crimes in general, but locking people up doesn't fix shit, and those people often embrace crime because the rest of the world wanted to make it hard for them to live a crime-free life. Even a murderer can be a productive member of society of you can rehabilitate them, albeit this might not be possible in all cases, but at least in some, it should be.