Fruits of the Poisonous Tree (Joe Gunther Mysteries)

The call came at four in the morning. An unknown intruder had broken into the home of a local woman as she slept. Tying her to the bed and blindfolding her, he indulged in a little knife play, destroyed the bedroom, and raped her repeatedly.
For Brattleboro police lieutenant Joe Gunther, the case cuts deep: the victim is his long-time lover and best friend, Gail Zigman, and the attack took place in the very bed he left just a few hours earlier.
The leafy streets, sweet with earthy scents of the nearby Vermont hills, yield a sour trail of unsavory clues, all pointing to vagrant handyman and ex-con Bob Vogel. With three rapes already to his name, it looks as if he's been at it again.
But appearances can lead to assumptions, and although Vogel runs for cover as soon as he's approached by the police, Joe cannot ignore the nagging feeling that something is amiss. Risking his friendship with Gail, the respect of his peers, and finally his own life, Joe doggedly keeps on the trail, trying to find out if the evidence against Vogel is genuine, or tainted...what policemen call "fruits of the poisonous tree."