I have written a few mysteries of the type known as cozy mysteries. This genre is also popular in television shows, the type you can watch with your children or your grandmother. Maybe that sounds boring to some who are looking for more gore or sexual content but there's a place and an audience for everything. Television shows like Murdoch Mysteries set in early 20th century Toronto or Death in Paradise, located on an imagined Caribbean Island (but filmed on Guadeloupe) in the present time. An interesting location or time adds to the mystery.
One of the problems I have discovered arises from the limited budgets that television programs have as well as the constraints of time after commercial interruptions are taken into account. The whole point behind the mystery is that it is difficult to know who the perpetrator is and the show usually revolves around the detective(s) following various trails in an attempt to uncover the truth. The audience of both the programs and similar books enjoys matching wits with the show writers. But this is where the constraints of television enter into the picture.
I was enjoying a recent season of the latter program when a small scene was played out involving an incidental character. It seemed a little out of place to my writer's mind and used up valuable air time. The character didn't appear again so I was prepared to discount my suspicions--I'm not that perceptive apparently. But just when all appeared to be lost, the brief scene did in fact play a pivotal role in determining the culprit. Vindication all around!