Unfortunately prosecutions would be difficult.

That extensive documentation has run smack into a hard reality, however. While authorities have amassed a staggering amount of evidence — the conflict is among the most documented in human history — they are unlikely to arrest most of those who pulled the trigger or gave the beatings anytime soon, let alone the commanders who gave the orders and political leaders who sanctioned the attacks.

The reasons are manifold, experts say. Ukrainian authorities face serious challenges in gathering air-tight evidence in a war zone. And the vast majority of alleged war criminals have evaded capture and are safely behind Russian lines.