Long story short, a few months ago, during an interview for one of his upcoming movies he recounted a personal story in which a female friend of his told him she'd been raped. The only thing she knew for sure about her attacker was that he was black. Well Liam Neeson then enraged spent the next week walking around town with a weapon hoping to be confronted by, and thus having a reason to beat up any "black bastard" as he put it in his recounting of the story.
If you do a google search for "Liam Neeson controversy* some news articles should pop up about the whole thing, as well as people's various reactions to his confession. Here's one such story from The New York Times,
https://www.nytimes.com/2019/02/04/a...on-racist.html.