I don't think it's a widely known story in general. I've not come across it very often in mainstream media or common knowledge. But it could be a very specific regional or niche story that some people are aware of.
Well, if 'Massacre Mike based on a true story' is a local or not - so - well - known story, it might be difficult to find detailed information. Maybe it's about a person named Mike who was involved in a tragic event that was later turned into a story. It could be related to a historical event, a crime, or a disaster. However, without further details, we can only guess.
Mike is not based on a true story. It's likely the product of the author's imagination or a combination of various fictional elements to create an engaging narrative.