MY FIRST FEW WORDS:

In the following message I just put forward the suppositions and tried to bring out a logical explanation for each supposition. Which is reasonable/relevant to what extent still depends on factual information/evidences to support it. I did not give any affirmation or drew any conclusion about the incident (note the words "possibility", "if" , ... used in the entire message) because I could not verify the information I read were true/correct (to some extent) or not. Anyone has better information or proper argument please let everybody know. Of course only the police was able to collect and verify all the facts needed.