There is not a shred of evidence that Putin had anything to do with Nemstov’s demise. Arrests have been made; there will be judicial proceedings.
As if Putin would somehow benefit from the slaying of a has been political opponent with about a 1% approval rating compared to his own 89.9% (the latest) just steps from the Kremlin.
You can live in whatever dreamworld you wish. If you want to try to convince people that Putin is just too nice a guy to be involved in killing people, that will be your challenge.
I'd like to see that. Why don't you go ahead and tell people that Putin is too nice a guy to be involved in killing people? Tell people what you know about him in that regard.
Meanwhile, don't let Putin's laughing at you bother you. You go right ahead and tell people what you know about Putin that convinces you he's too nice a guy to kill people.