Wow, that is one scary news ! To be killed unexpectedly when living under one roof, there must be some misunderstanding that had happened.

Or maybe the boyfriend’s brother is a psycho.
I agree that dating online can be mysterious and refreshing but it is also dangerous as you had mentioned.

It is wise to date casually, physically and not visually.

At least, you can see the other party face to face, able to know his or her characteristic, behavior besides talking about the appearance.

Mutual friendship or acquaintance would be nice and safer.