Based on a 'True Story'? Erm...
...just as well say its based on a real dream.
Its all so very unlikely and I'm sure that if there was truth at the root of it all, it was a person with extreme mental issues, or someone wanting to sell a story for a quick buck or-just an attention seeker. That's what made it all the less scary for me.
If it were an admitted known work of fiction, then it could be taken more seriously AS a work, but when it has that 'Based on real events' tag- it loses a lot of oomph.