[marktwain]

Unknown does not mean that you do not know your murderer. It just means they do not have enough evidence to charge anyone.

Yes, it means the authorities do no know who the murderer is, and therefore, they do not know the relationship of the murderer to the victim.

Murders where there is no connection between the murderer and the victim are usually the hardest to solve.

[Harmless Teddy Bear]

Yes, it means the authorities do no know who the murderer is, and therefore, they do not know the relationship of the murderer to the victim.

Actually they may have a pretty good idea who the murderer is but just no proof.

Without enough proof, no case.

Murders where there is no connection between the murderer and the victim are usually the hardest to solve.

Yes. Motive unknown makes it hard to know where to look.