Intensity Series by Aspen Drake, Emily Cain, Operation Alpha

Sierra has believed her dad was one of the good guys for her whole life. When she's confronted with evidence that the man who tried to kidnap him is actually saving the world from her father's evil ways, everything gets turned upside down. She tried to resist Parker for as long as possible, but after spending time with him, she realizes what she's been looking for is right in front of her. 

 Parker works for the international division of Chase and Sadie's company in Fort Hood... moreSierra has believed her dad was one of the good guys for her whole life. When she's confronted with evidence that the man who tried to kidnap him is actually saving the world from her father's evil ways, everything gets turned upside down. She tried to resist Parker for as long as possible, but after spending time with him, she realizes what she's been looking for is right in front of her. 

 Parker works for the international division of Chase and Sadie's company in Fort Hood. When the daughter of the man he's hired to eliminate offers to take her father's place, he is intrigued by her bravery. When she proves to be talented in self-defense, shooting, and holding her own in a verbal match, he realizes he's met his match.

 Parker doesn't do the girlfriend thing, but despite his attempts to fight his attraction to Sierra, their connection is too strong to ignore. less

The sequel to Parker and Sierra's story. Sierra wants to help capture her father, but she isn't sure she has what it takes to face the man who raised her with the cold-blooded attitude needed to take him down. When she finally does, he surprises her with truths she never would have believed.With Parker finally accepting her into his life, she has to make a decision about how her criminal father might also be there too.