Poor Tom Is Cold (Detective Murdoch #3) by Maureen Jennings

While hunting down the killer of a constable from his station, Jennings' likable detective, William Murdoch, is drawn to the plight of a young wife whose predatory stepchildren plan to shut her in an insane asylum to prevent her inheriting her husband's estate. With her ability to invoke the Toronto of a century ago and its many levels of society, the author finds under stones of silence the social outrages that so vividly trigger her mysteries.