There must be more to the plot with the Tanner Rejiek Hidesman and the skinner murders because you cannot kill this guy in in his shop. I got tired of him always escaping, so I surrounded him with monsters, animals and nymphs before initiating dialogue again. When he turned red he couldn't escape the encirlement and I hit him with everything I had. After all the spells were used and arrow quivers emptied, it was all hand to hand. His status was near death nearly the entire time, but after dishing out well over 3k points in damage I knew he couldn't be killed here. Is there more to his plot, do I find him again somewhere else and finally get to finish him off?
Simple answer is sufficient, I don't want to much of a spoiler. Thanx all.

You're supposed to follow him or u will miss key plot items.

Thanx Glorick the Half-Orc,
I followed him down to the second level, then to the third, but he's already gone when you get there, he's aparrently taken off in a boat, and you have to dispatch his pals. I found the letter, so I know I have to track him down and use the ciphered code therin. Thanx again.

Slight Spoil
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The letter you find refers to a contact in the Umar Hills. The code refers to the alphabet when counting back/forward from letters, to work out contact's name. You will need to get his name right first time, after buying the book, or else he walks. He will ask for the skin plus another item to make armour for you.

Another spoiler.
Rejiek fled to Trademeet. Complete the Dao and Druid quests there and you'll become involved in the quest to kill him. I found this quest a bit dodgy compared to its counterpart in the Bridge district, but anyway. "Skin Dancers"? Uh-huh.