At first, Cabot Cove doesn't seem all that bad. It's an idyllic coastal community of only 3,000, so you can't complain about the atmosphere. Also, for a town in the typically unwashed state of Maine, the townsfolk are relatively attractive, consistently looking (and for some reason acting) like they just stepped off the set of a soap opera.
However, none of that changes the fact that if you lived in Cabot Cove from 1984-1996, there was a pretty good chance that someone was going to murder your ass. With a body count of up to eight per episode, Cabot Cove experienced an outbreak of no less than 800 murders during the time that Jessica Fletcher lived there. And the crimes tended to be local on local, meaning that over half of the population was involved in a murder in a twelve year span. (Hear that, Camden, NJ?)
Law Enforcement:
In a small town like Cabot Cove, you'd think that the limited suspect pool would have enabled the cops to solve murders pretty quickly. But time after time, the Cabot Cove PD would arrest the wrong person, falling for clearly planted clues like a suspect's hat being left at the scene of the crime, and ignoring obvious culprits like the guy in the corner laughing maniacally while steepling his bloody fingers.
Sure, Jessica Fletcher would set the cops straight in the end, but not before the cops would tell her to "leave this one up to the professionals." And just imagine what happened when the swinging queen of crime fiction was off on one of her many vacations. (Where people coincidentally were also always getting murdered.) If you live in Cabot Cove, you're either going to commit murder, get murdered, be falsely accused of murder, or you're a shyt-stupid cop. Take your pick.