Short Answer 
The murder of a gentleman by Mr. Hyde initiates a mystery, prompting police to collect crucial evidence like a half walking stick and a letter to Mr. Utterson. The investigation intensifies as Inspector Newcomen asks Utterson to identify the victim, leading them to further incriminate Hyde through additional evidence discovered at his residence.
Step 1: The Murder Incident
The sequence of events begins when Mr. Hyde commits an inexplicable act of violence by murdering a gentleman in the street. This shocking incident sets the stage for the unfolding mystery and raises questions about Hyde’s character and motives.
Step 2: Evidence Collection
Following the murder, the police discover crucial evidence at the crime scene, including half a walking stick and a letter addressed to Mr. Utterson. These findings are significant as they establish a connection between Mr. Hyde and the victim, which leads to further investigation.
Step 3: Identification and Investigation
The investigation progresses when Inspector Newcomen requests Mr. Utterson to identify the body of the murdered man. Together, they visit Hyde’s residence, uncovering more evidence such as another half of the walking stick and a burnt checkbook, deepening the mystery surrounding Mr. Hyde’s involvement in the murder case.