Trust Me (The Donovan Family #4)
Margaret Watson

When Detective Connor Donovan answers a call about a trespasser outside Northrup's house, he finds a woman running down the street. When he tries to stop her, he's left holding her hoodie as she strikes out like a ninja then vanishes like smoke.
Connor quickly realizes Raine is his mysterious trespasser. Now he has to figure out why she was outside Northrup's house at three A.M. Raine isn't his usual criminal – she's a schoolteacher who coaches a tae-kwon-do team of under-privileged girls. And he's wildly attracted to her.
Raine needs to stay away from Connor. She has a plan to deal with Northrup, and she can't get involved with a cop. But like two magnets drawing together, she can't resist him. Can Connor help her find justice for Genie? Or will her sister's killer claim another victim before they can stop him?