Romance book about a cop that is also part of a gang. He falls in love with the gang leaders sister. The gang leader entrusts him to protect his sister. He moves into the apartment next to or across from hers to keep an eye on her.

[Kay]

He lives a double life. He’s been part of the gang for a long time because his brother was also in it. The gang members don’t know that he is also a cop. He meets the gang leaders sister and falls in love with her. I read this book about four years ago.

[Maria (semi hiatus)]

Undercover by Kasey Millstead

[Kay]

No, it is not Undercover. The book was part of a series. Every book was about a different couple. I believe the book I’m looking for is the second book in the series. The first book in the series is about the hero’s brother.