Josiah Amberley is the main antagonist of the Sherlock Holmes story The Adventure of the Retired Colourman.
A retired art supply dealer, he lived with his wife in Lewisham, however being a incredibly miserable and unpleasant man, he drove his wife away, and she found comfort in the hands of their neighbour, Dr. Ray Earnest.
Consumed with envy, and believing the two to be having an affair, Amberley desired to murder them. He had lured them into the strong room, locked them in and then using a gas pipe he had installed, filled the room with Gas, suffocating them both.
He then hid the bodies in his garden, and also hid multiple valuables belonging to himself, and claimed that they had run off together stealing his valuables. He also began painting his house to cover the smell. Being a smug man, and arrogantly convinced that no one could find out the truth, Josiah contacted Sherlock Holmes to investigate his wife's disappearance. As Holmes was to busy, he sent Watson to investigate and noticed several peculiar things around his house, including his painting.
Amberley, claimed he had gone to the Theatre when she disappeared, claiming she didn't come due to having a headache, and produced his wife's unused ticket as proof. However Holmes investigated and met up with another detective a Mr. Barker who had been hired to investigate the disappearance of Dr. Earnest by his family. The two agree to work together, seeing from Amberley's character that he is a miser, and a jealous man. As well as being a chess enthusiast, coupled with a few other pieces which don't fit, leads Holmes to determine what truly happened.
Confronting Amberley, Holmes demanded to know what he did with the bodies. Realizing the game was up, Amberley tried to commit suicide by a pill, but Holmes managed overpower him. Holmes then revealed that Amberley's alibi fell apart when he found that his theatre seat hadn't been sat in on the night in question. Amberley is arrested though Holmes believed he would go to Broadmoor Hospital (a psychiatric Hospital) rather than hang, due to his unstable mental state.