The Edge of Winter (Danny Carlisle Mysteries, #1)

A powerful man is found dead in his fish house on a frozen Minnesota lake, murdered, stabbed to death. His employees, family, and the local sheriff, all seem happy to have him gone - all except his personal assistant. With his death she is now forced to do something she thought she would never have to do, reveal secrets that will destroy the careers and lives of many - including a man set on being the next governor of the state.
Minnesota Bureau of Criminal Apprehension Agent Danny Carlisle has been given the assignment, her first as a lead agent, and she and her partner soon find they have too many suspects and too little evidence. But someone is doing them a favor, narrowing down their list of suspects by killing them off. The snow and bodies in Duluth accumulate, and Carlisle's boss is pushing her to find who is doing the killing, someone who seems to know her every move.
Readers of John Sanford, Sue Grafton, Sandra Brown, Jeffrey Deaver and alike should enjoy this thriller.