The Other Side of the Door by Lucia Chamberlain

It's 1865 in the city of San Francisco. Pretty, young Ellie Fenwick is walking to the market early one morning to surprise her father with some fresh mushrooms. As she passes a gambling house, she hears a gunshot and two young men emerge. One man falls dead on the pavement and the other is Johnny Montgomery, a handsome young man Ellie recognizes from seeing him previously at a dance. Johnny is holding a smoking pistol in his hand. This incident propels the proper young Ellie into a world of prisons and courtrooms as a murder trial unfolds and the fate of Johnny may rest with her testimony. But, what is the connection with the mysterious Spanish Woman, who lives in a grand house and supposedly has friends in 'high places'? Who else was in the gambling house at that time of the morning before it had opened? What about the whispered conversations between Ellie's father, Mr. Fenwick, and his friend, Mr. Bingley, a prominent attorney prosecuting the case? Things are not always what they may...