Final answer:
The murder of Sir Danvers Carew in 'Dr. Jekyll and Mr. Hyde' was witnessed by a maid. She described the event, which contributed to the subsequent investigation.
Step-by-step explanation:
The murder of Sir Danvers Carew in the novel 'Dr. Jekyll and Mr. Hyde' was witnessed by a maid. She is the one who, from the window of her room, sees Mr. Hyde meet with Sir Danvers Carew and then brutally beat him to death. The maid's account is significant as it leads to the further investigation into the strange and dual character of Dr. Jekyll and the hideous Mr. Hyde.