The many parties involved complicate war crimes investigations.
A Russian missile strike on a city in central Ukraine on Thursday killed at least 23 people, including three children. Two weeks earlier, missiles crashed into buildings near Odesa, killing 21. And for weeks in the Kyiv suburb of Bucha, civilians bore the brunt of Russia’s assault — killed on their bicycles or while walking down the street, or executed with their hands bound.

Indiscriminate Russian attacks on civilian areas have become a hallmark of its invasion, and this week, an international conference in The Hague sought to coordinate an approach to the overwhelming allegations of war crimes in Ukraine.

But investigators face a formidable challenge, with as many as 20,000 war crimes investigations, multiple countries and international agencies at work, and a high burden of proof to reach a conviction. Complicating matters further, investigations are working while the war is still raging. The Kremlin has denied allegations against its forces, and Russia’s Defense Ministry has called graphic evidence of atrocities “fake.”