The Image of Valor. Valorie Dawes Thrillers, #7

The Engineer has a mission: to clean up the human gene pool. His method: killing women who have what he considers "defective" DNA. His primary victims are members of a self-help therapy group focused on body-shaming and body-image issues. The group includes two of Val Dawes's closest friends-and before long, Val becomes a target as well. Now the youngest-ever detective in the Clayton City Police, Val goes undercover to track down how the killer is identifying and isolating his victims.
Soon the group becomes a powerful tool for her addressing own latent body-image issues. When her favorite, quirky barista goes missing, Val goes all out, willing to do whatever it takes to stop "The Engineer" before his killing spree reaches epidemic proportions. Can Val find her friend before she, too, falls victim to a deranged vigilante?