Black Dog (Cooper & Fry mystery series Book 1) by Stephen Booth is 99 cents for Kindle today. The cover blurb says:
Who killed Laura Vernon?
The helicopters are halted. The dogs are called off. The search for beautiful, teenaged Laura Vernon is over. Her body is found, mutilated, in the forest.
When he takes on the case, Ben Cooper is paired with a new partner: Diane Fry, a woman as tenacious as she is alluring. The two detectives are like fire and gasoline. But they must learn to work together to apprehend a killer who is hiding in plain sight.