Mystery Puzzle

It's my first attempt to write a mystery story, please go easy on me. :) and suspense it waiting for you at the end...

Any resemblance to real persons or other real-life entities is purely coincidental. All characters and other entities appearing in this work are fictitious. Any resemblance to real persons, dead or alive, or other real-life entities, past or present, is purely coincidental.
Beware of grammatical mistakes and it's advisable to have detective music in the background >_<