Detective Inspector Dimmock is an inspector of New Scotland Yard. He was called in when Sherlock found a dead banker's body in a man's flat. Dimmock first believed the banker's death to be a suicide, and needed a significant amount of convincing from Sherlock to believe that it was murder. Sherlock pointed out that it would have been difficult for Van Coon to have shot himself in the right side of his head when he was left-handed, and at Dimmock's scepticism, proceeded to point out each piece of evidence that pointed to a left-hander.