I'd be more shocked if there is a revised version of the Bible that tries to make Moses into a murderer.
Oh if you mean Paul, then it's possible he was a murderer, it just says he persecuted the Christians, not neccessarily that he murdered them, though I suppose you could in fairness consider him complicit in the murder of saint Stephen.
Moses isn't a murderer, the Egyptian deserved to die because he was an idolator of a foreign race that was beating Moses' people. Murder is killing someone that is innocent.
As for David he was still pretty cursed for his sins worthy of death, don't make any mistake about that. It's not like God just winked at him for it and gave him a pass, David still had to pay the consequences and David at least knew he was wrong and did not defend that which he did. It's not like David tried to browbeat Nathan or cancel culture him for telling the truth about why he just earned a big curse.
There's a fine line between mercy and defending the wicked. Whoever wants mercy go on ahead and forsake the wicked, forsake defending them, forsake their entire army and kingdom, and come and obtain mercy.