The answer is quite simple...

The murderer was;

>! rand al'thor

Why? It was all part of the plan...

>! He had killed his Lordship and then came to stack exchange explaining *his version of the story* in which he was not mentioned in. He then decided to take **OUR** answers and give them to the court. He never mentioned himself in the story at all, therefore he never appeared in any answers. He attempted to blame someone else, but tricked us into helping in his elaborate scheme.

How was he killed?

>! With whatever other elaborate scheme rand used. I guess he framed an icicle so probably something else.

Comment for OP;

>! Nice plan/scheme you had there ;D