As a regular obit writer, this is a recurring fear, when a key part of the colourful life you profile turns out be a fabrication.

Cuban-born novelist and classical pianist Hermán G. Carrillo was actually Glenn Carroll of Detroit, Michigan. https://www.washingtonpost.com/local/cuban-american-author-hg-carrillo-who-explored-themes-of-cultural-alienation-died-after-contracting-covid-19/2020/05/21/35478894-97d8-11ea-91d7-cf4423d47683_story.html

Good thread from @jasminnemendez about a key question in this story that might never be answered because Carrillo/Carroll kept it his life secret. https://twitter.com/jasminnemendez/status/1264718140115685376

The challenge when writing obits is that often for large parts of a person's biography, you have to rely on their words, what they have said about themselves, what they told relatives and coworkers. There is only so much you can corroborate via public records on a deadline.