I understand what you're saying, but it's a fine line that gets walked when it comes to series. People return to sequels (movies/books) because they loved the original. You venture too far from that and you annoy the crap out of many people. I definitely think there should be advancement. I also agree with the term 'mindless entertainment" and I do not see that as a negative statement. Sometimes you need to just veg out. Heck, I would label some of the books I have written as mindless entertainment.
As for new criminals/killers in a small area. I don't know that that doesn't fall into the area of suspension of disbelief. Look at tv shows like Murder She Wrote or something like Heart to Heart. Is is believable that every where Jessica went someone turned up dead? She was small town Maine I believe and did it seem 'believable' that everywhere The Harts went someone died or a new mystery turned up? Not saying you are wrong in your opinion, just seems like a matter that the author was unable to get you to suspend your disbelief.
Oh and if you happen to run into a guy named John McClane, especially around Christmas time, get the heck away from him ASAP. ;)
As for new criminals/killers in a small area. I don't know that that doesn't fall into the area of suspension of disbelief. Look at tv shows like Murder She Wrote or something like Heart to Heart. Is is believable that every where Jessica went someone turned up dead? She was small town Maine I believe and did it seem 'believable' that everywhere The Harts went someone died or a new mystery turned up? Not saying you are wrong in your opinion, just seems like a matter that the author was unable to get you to suspend your disbelief.
Oh and if you happen to run into a guy named John McClane, especially around Christmas time, get the heck away from him ASAP. ;)