The Moments You Miss (The Whispering Killers #1) by Mae Roberts:
 
Leyla Clarkson's world was shattered the night her family was murdered. Years later and running from chilling reminders of her past, an unexpected reunion with her childhood friend, Cameron Curtis, brings a glimmer of hope — and a dangerous darkness she never saw coming.

Cameron, once the sweet boy she met in the midst of grief, is charming and irresistibly magnetic, but he seems to be hiding his own dark secrets. As their connection deepens, Leyla is torn between the friend she once knew and the mysterious man he’s become.

As their relationship unfolds, betrayal, obsession, and violence push them to the brink of sanity. Leyla and Cameron are forced to confront their pasts, their demons, and the undeniable pull between them.

Can love survive in the shadows, or will the darkness consume them both?