Jabez Wilson was a fictional character from the Sherlock Holmes story "The Red-Headed League".
In 2365, Data, while masquerading as Sherlock Holmes, saw Jabez Wilson walking down the street toward the home of the Red-Headed League and deduced from a bell cord and a running youth that he was about to become the victim of a murder.
Although Wilson was never in danger of being murdered in the original story, the holodeck had created a program based on several Holmes stories, and Data used his knowledge of these stories to come to his conclusion. (TNG: "Elementary, Dear Data")
Jabez Wilson was played by an actor whose first name was Brian, and received no credit for this performance.