Strange Love - Dark Knights in the City, #2

Luca has had his eye on the woman who eats at his restaurant with her friends each week. When his delivery driver is late, he fills in and discovers her drunk, lonely, and in dire need of a spanking. Too bad Luca doesn't have time for romance. He's too busy working to take down the kingpin of the underworld, with his cronies, a group of like-minded guys. When they find out she's digging around in their business, they want her to disappear. Heidi Jones wants romance with Luca, but she always picks the wrong guy.
Based on the research she's doing on the city's changing crime patterns, this time, she picked the worst. It's too late though. He's already got her and he's not letting go. He says he's protecting her, but she thinks it's something else.