The problem is no one is sure if their laws are causing this. Why? They're not really open with how things are done. Do you have any studies to say otherwise? Right now all the studies show it doesn't work.
You can call out Japan because it's well known they do handle things oddly. Osaka, Japan was caught doing this:
http://www.japantoday.com/category/...e-admit-hiding-81000-crimes-to-clean-up-image
The problem with a lot of these countries is they're generally not open to sharing how things are handled behind the scenes. You can't really study things you're not allowed to see.
What contributing factors?
Let's look at the murder rate per state in the USA:
http://www.deathpenaltyinfo.org/murder-rates-nationally-and-state#MRalpha
http://www.amnestyusa.org/our-work/...enalty-facts/the-death-penalty-and-deterrence
You're not going to find anything substantial that says the death penalty or punishment oriented sentences work.
I can't argue with this. There's no data to show diversity overrides rehabilitation.
It is a melting pot, yes, but you haven't adequately shown the death penalty or punishment in general acts as a deterrent. This topic has been studied many times before. It does not work.
You have to raise an eyebrow when someone defends the death penalty and then says this person needs rehab. It makes you seem not confident in your argument because you recognize a way that works better.