Glass of Wine Anyone?

     At the beginning of The Last Night section within Stevenson's "The Strange Case of Dr. Jekyll and Mr. Hyde", Poole visits Mr. Utterson under the most unpleasant of circumstances. Poole comes to tell Mr. Utterson about Mr. Jekyll's seclusion into his cabinet and to urge Mr. Utterson to return to Jekyll's place with him. What stuck with me after leaving the passage was the reoccurrence of the phrase, and the mention of, "glass of wine". Utterson offers Poole the glass of wine when he firsts arrive. This offering was typical of a host to his or her guest. However, in the case of Utterson's offering to Poole, it seems to be a way of calming Poole down, in addition to Utterson's hosting duties. Utterson gives Poole the glass of wine, then tells him to "take your time" before telling his story (page 851). Poole, however, is overcome with his fear, saying he "can bear it no more" (page 852). After this declaration, the narrative comments upon Poole's countenance which "amply bore out his words" (page 852). The glass of wine appears to be an afterthought as it sat "untasted on his [Poole's] knee" (page 852). In my opinion, the glass of wine symbolizes a traditional visiting scenario: a guest would arrive and ask admittance, the host or hostess would greet them and offer them refreshments before moving on to the typical trivial talk of gossip or fashion for the ladies and politics for the men. Poole's unconscious rejection of Utterson's glass of wine points us to the fact that this is no typical visit. The manner of Poole's visit is one that would be deemed "socially unacceptable", hence the rejection of society's dictations on this particular visit. Indeed, as Mr. Utterson prepares to leave with Poole after hearing his plea for help, it is noted that "the wine was still untasted when he [Poole] set it down to follow [Utterson]" (page 852). For me, this pointed to the depravity of the situation that was to come.

Why are the police not involved when the body is discovered? I did not understand the significance of the rusty key that was found on page 857. Any thoughts?