Where There's Smoke, by Cathy Cole
Homes are burning in the small town of Mourne Lough, and Firefighter Jo Woods suspects arson. Her superiors don't share her conviction and order her to stop investigating. Jo can’t, not after she finds the roses. She first saw them the night her family died. Now, seven years later, another family is dead. Murdered. And she is determined to prove it.
Propelled into a dangerous quest, where everyone has an agenda and no one is quite what they seem, Jo finds herself alone and friendless in an unfamiliar town. To expose the killer, Jo must discover who, or more importantly, who not to trust, because the killer is a lot closer to home than she realises.