Motive in a true crime story can vary widely. It could be greed. For example, someone might have committed a crime to get a large inheritance or financial gain.
I'm not sure which specific 'the secret true crime story' you are referring to. There are many true crime stories out there that might be considered'secret' in some sense, perhaps because they involve long - hidden details or overlooked aspects. It could be about an unsolved mystery, a crime that was covered up for a long time, or a case that had some unexpected twists.
I don't know the details of your family's story. It could be anything from fraud within the family business to a long - hidden murder mystery. Only your family members who are aware of the secret can truly disclose it.
In many cases, crimes depicted in various forms of media might have elements drawn from real-life incidents, but they could also be heavily fictionalized for entertainment or narrative purposes. So, it varies.
In many cases, true crime stories are based on real events and facts. But sometimes, there might be some dramatization or artistic liberties taken for the sake of storytelling.