The murder of Jon'Benet Black

You've decided to go to your desk at the 3rd floor in FBI Headquarters. The room is in a complete mess since you've been busy with the previous cases that took so long to be solved. Suddenly, someone from the agency that you haven't met before knocks at your door. You glance up as she approaches. You see a slight young woman with pale features. "So. You have returned..." The woman takes a rasping breath, then breaks into a violent coughing spell. "Don't you have any time to take care of your room, sir?" You exhale irksomely and don't respond to her. Then, she leaves a file on your desk about the murder case that you're appointed to. "This is all we've got, at least for now." As she leaves the room, you pull up your chair and open the envelope gently. Opening the envelope, you find 3 papers; a ransom note, police interrogation report and the crime scene investigation report.