Chameleon's Challenge — B.R. Kingsolver

Libby's chameleon mutation has led to a lucrative career as a thief and assassin. She normally doesn't worry about the comfort of corporate executives, but when she stumbles onto the grisly murder of a rich man's mistress, it gets her attention. The murder leads Libby to believe her best friend's life is in danger, and she vows to protect her. The killings continue, some in broad daylight, but no one ever sees the killer.For a chameleon assassin, the scenario feels uncomfortably familiar.