Really? You're totally unaware of programmes like Crimewatch, then? Or the fact that SKY has an entire channel dedicated to real life crime? Or the entire sections in bookshops dedicated to it? Or all the documentaries on Netflix about various crimes and serial killers? Piers Morgan has just released several filmed interviews with serial killers, for example. I very much doubt that all that has totally passed you by - unless you've been living under a rock for the past forty years.
What you really mean, is that you think people who are interested in true crime are freaks or weirdos, so you're pretending you're totally oblivious to the whole thing.
I'm aware of Crimewatch. A programme that puts out appeals to try to help solve crimes. That isn't what we are talking about.
I wasn't aware Sky had a channel entirely dedicated to real life crime, no. Why would I be ? I don't have Sky, and I don't have an interest in poring over gruesome crimes. 
I don't have Netflix either, so, again, wouldn't happen upon it there.
I have been in bookshops, obviously, but only tend to go to one very occasionally when looking for a specific book, and I'm sure there are books on any subject you want if you go looking for them, but I've not 'happened upon' the fact there are so many, though I'm aware there are always people out there ready to try and make money on the back of someone's misery.
I very much doubt that all that has totally passed you by - unless you've been living under a rock for the past forty years.
Well, putting aside the fact that neither Sky nor Netflix have been around anywhere like that long, I haven't 'been under a rock', just clearly have other interests. That's not so strange is it ?