Understanding what happened in Bucha

Josh Marshall at Talking Points Memo has flagged articles from Der Spiegel and the Wall Street Journal that together paint a grim picture of how the Russian occupation of Bucha, Ukraine started as a simple occupation but quickly devolved into hellish war crimes against the civilian population. Sounds like a combination of an undisciplined occupying force that became increasingly paranoid as they started taking casualties, and direct orders from above to purge politicians and other Ukrainian nationalists.