I don't know about 100%, but it is quite a common thing. That said, even if you make a crime/situation/scenario up entirely, there is a good chance it has happened somewhere.

Case studies of actual investigations - what worked, what didn't, what the big break was, etc - are not uncommon in law enforcement academies and training.

When you watch stuff like CSI and Law & Order, their criminal investigation stuff is often about as accurate as their high tech and computer science stuff.

Law and Order certainly pulls a lot from real cases, but it's not that high of a percentage. I'm sure many are inspired by multiple cases mixed together but most murders are pretty boring by fiction standards.