Body of Natsumi Kogawa was found inside Gabriola Mansion on Wednesday evening
TokyoReporter
Officers warned shopkeepers against payment of protection money
Court ruled that location in mountains rendered it 'not visible to outside parties'
Victim was found collapsed and bleeding from stab wounds to his chest and abdomen
Suspect covered victim's mouth and fondled her chest
Suspect approached victim from behind and snatched her bag
Suspect lured victim out with promise of ¥20,000
Suspect also stashed 0.1 grams of the contraband at home
Suspect stalked girl, lingered at crime scene
Some cops are alleged to have threatened 'to strangle' the participants