Why are we just now hearing about this? In fact, I’m unclear as to why an article was published about it now exactly.
The “black blood” he vomited was presumably blood he had been forced to swallow, or swallowed voluntarily, while in the presence of his new vampire informants/friends in Poland, who were the last ones to see him alive.
This case is an amazing part of history. I wonder if we will ever know more about what happened.