Unfortunately I think it is going to get a lot worse. I don't believe Becky would be the type to engage with strangers given her character. In my opinion only, I believe who did her harm was known to her. And if that is found to be the case in time, I am guessing known to the family also. Which must be horrific. Especially if (and I don't know this for a fact obviously) (just speculation) someone known to the family knew more than what they were telling and lied to the family or even saw their pain and distress and didn't come forward- can you imagine the betrayal?
However we still do not know what happened. If the body was not mutilated and efforts to dispose of her- I would hope it was some sort of accident or a fight that got out of hand or even a drug related death- anything less barbaric than this.