Murder At The Luther, by Kathleen Kaska:

Confident and free-spirited redhead, Sydney Jean Lockhart, has shunned the entrapments of marriage and domesticity in order to maintain her independence and pursue her career as a reporter.
Attending the “Neptune Rising” themed Ball on New Year’s Eve, she finds herself evading the unwanted attentions of undesirable suitors, befriended by various socialites, and looking forward to a bird watching date with used car salesman, Sam Buckner.
In the midst of party revelers, champagne and dancing, a murder occurs and Sydney Lockhart is discovered standing over the victim with his blood on her hands.
Pursued by Police Chief Lynol Fogmore, a cigar-chewing bulldog of a man, hungry for a fast arrest and conviction, Sydney finds herself his number one suspect. In a race against time to prove her innocence, she sets out to solve the case and unmask the real murderer.
Kathleen Kaska’s book is a neatly written, fast-paced and entertaining thriller. Her central character, Sydney Lockhart, is a feisty, strong and believable heroine, embroiled in a charmingly nostalgic murder-mystery, reminiscent of the classic Agatha Christie style whodunits that would also transfer successfully to stage and screen.