DR Murderer x normal girl

So what’s this book called? So I think this might have been a collage romance, or she was working, but they were in there 20’s and he kills someone I believe for her, and he’s a serial killer, and he shows up at her house, showers in her shower, burys the guy in her backyard, I think he washes his clothes in her home, so he blackmails her, the guy he killed was bothering her. I’m sorry there’s such little details please and thanks in advance! 💗