How do people form beliefs about the factual content of major events when established geopolitical orders are violently challenged? Here we address the tragic events of May 2, 2014, in Odesa, Ukraine. There, Euromaidan protest movement supporters and opponents clashed following Russia's annexation of Crimea and the onset of the Donbas conflict, culminating in the worst civilian death toll the city had seen since World War II. Shortly after, we surveyed Ukraine's population about who they thought had actually perpetrated the killings and relate people's answers to alternative narratives (frames) that an original content analysis finds were available to Ukrainian citizens through different media. We find evidence, consistent with theories of hot cognition and motivated reasoning, that the Odesa violence triggered emotional responses linked to ethnic, regional, and partisan identity, which then activated attitudes associated with these identities that, in turn, led people to adopt very different (sometimes highly improbable) beliefs about who carried out the killings. Ethnic identity in particular is found to have strongly moderated the effects of television, with Ukrainian television greatly influencing Ukrainians but backfiring among Russians, and Russian television mainly impacting non-Ukrainians. Education and local information are found to reduce susceptibility to televised factual narratives.