Promise Her (The Callahan Series)

Lisa Kane has almost everything: a good job as a private investigator, a fun hobby as a barrel racer, and a wonderful horse. What she doesn't have is the man who stole her heart the moment she met him. Attorney Douglas Callahan loves her all right--like another sister. But that isn't what Lisa wants. Douglas's reputation with women is well-established: love-'em-and-leave-'em. But when Lisa becomes a suspect in a murder case she's investigating, he feels an unexpected tug at his heart. Just brotherly concern? Or something more? After her saddle is sabotaged at the rodeo, he insists on protecting her. Watching over Lisa, Douglas soon realizes what everyone else in the Callahan family already knows--she's his perfect mate. But with a killer trying to silence her forever, he's got to stop her from doing anything rash before he can convince her she's the one woman for him.