The Next One To Fall Lily Moore Series, Book 2.

Travel writer Lily Moore has been persuaded by her closest friend, photographer Jesse Robb, to visit Peru with him. At Machu Picchu, they discover a woman clinging to life at the bottom of an ancient stone staircase. Just before the woman dies, she tells Lily the name of the man who pushed her. When the local police investigate, the forensic evidence they find doesn't match what Lily knows. Unable to accept the official ruling of accidental death...