Murder on Bank Street: a gaslight mystery
(Book)

In the four years since her husband's death, midwife Sarah Brandt has become an angel of mercy in the tenements of turn-of-the-century New York, helping the less fortunate bring new life into the world - and, with Detective Sergeant Frank Malloy, seeing that justice is done for them. Now, in the latest novel in the Edgar Award-nominated series, Sarah finds justice herself.
Out of his affection for Sarah, Malloy has been taken up the task of solving the murder of Dr. Tom Brandt. The odds of finding reliable witnesses and evidence after four years are slim, but with the assistance of Sarah's wealthy father, Malloy has unlimited resources at his disposal - including Pinkerton agents answerable only to him.
Malloy discovers that Dr. Brandt was involved in the treatment of several dangerously delusional women. His suspicion is that the doctor's unsuccessful efforts at curing these patients led their families to question Brandt's methods - and ethics. Then to seek vengeance against him.
It's a good, solid theory, and Malloy has several suspects. But when he finally discovers what he believes to be the truth, the shocking revelation may destroy Sarah - and Malloy's hopes for any future with her.