Cold Blooded Lover by Eliza Lentski

Former Marine, Cassidy Miller knew what it took to be a good soldier and even a decent beat cop. She was starting to figure out how to be a girlfriend as her relationship with Julia Desjardin progressed, but what did she know about being a cold case detective?

Buried under paperwork in the basement of the Fourth Police Precinct, she was going to have to figure it out. An unidentified Jane Doe, an unusual poison, and a decade passing since the murder wasn’t going to make it easy on her. Plus a call in the middle of the night reminds her that as much as she might want to move on from her time in the military, some things would always keep dragging her back.