It’s been my experience that people believe what they need to believe.
In some cases, they believe this so intensely that we lock them up for their own safety.
In the Jeff Rice novel, “The Kolchak Tapes,” that the old “Night Stalker” TV series was based on, Rice addressed this issue very nicely, thank you.
NOBODY believed it. Not even Kolchak. Eventually, the cops and Kolchak develop the idea that the murders are the work of a loony who THINKS he’s a vampire.
Kolchak’s investigations lead him to the information that the killer is likely one Janos Skorzeny, an Eastern European with an odd and checkered record that, if believed, would make him something like a hundred years old. Even THAT isn’t enough to convince Kolchak, much less the cops.
Kolchak does begin to develop doubts, though, after a serious scuffle between Skorzeny and several police officers… in which the medium-sized Skorzeny grabs an officer twice his size, and pitches the cop over a fence like a sack of laundry.
Even then Kolchak does not voice his suspicions. At least, not loudly. He’s afraid of being labeled a kook. He does, however, convince the cops that carrying crosses and holy water are a good idea… because we have established as FACT that Skorzeny is insanely dangerous, even barehanded… and if Skorzeny thinks he’s a vampire, perhaps the crosses will do some good. The cops grumble, but even they see the logic in it.
The book – unlike the TV movie – does not end with Kolchak wandering into the vampire’s lair, alone, at night. Kolchak tracks Skorzeny to a rented house, and Kolchak accompanies a substantial force of police officers to the place, where it turns out that crosses and holy water are very much effective (there’s a hilarious scene involving Skorzeny and his coffin, which Kolchak has found earlier, and poured about a pint of holy water into. When Skorzeny tries to hide in the thing, he winds up erupting out of the coffin, screaming and hissing and “acting like he’d been shot in the can with buckshot,” as Kolchak puts it.
Only when Skorzeny has been run to ground do we discover that the chief of police is also convinced. He pressures Kolchak into driving a stake through Skorzeny’s heart… then arranges for Skorzeny to be cremated… and offers Kolchak a choice: keep your mouth shut, and preferably leave town… or face charges of murder.
I wish the book was still in print. It wasn’t what I’d call a great novel, but it dealt with the issue of “belief in the supernatural in today’s world” better than any other book I’ve ever read.