Unexpected Partners by Michelle Larkin

After she’s abducted and barely escapes with her life, Dr. Chloe Maddox joins the Boston Police Department as a behavioral profiler. Her sole objective is to solve her own case. The only thing standing in her way is she has no memory of what happened. When she locks eyes with the man who murdered her lover and left her for dead, the past comes flooding back. Detective Dana Blake is still mourning the death of her wife. When she discovers Chloe’s abductor is the same serial killer who took her wife’s life, she insists on protecting her. Both women are caught off guard by their developing attraction as they build their case, on the run from a clever sociopath. Danger lurks behind every corner, and a killer is intent on recapturing his prey. Except this time, he has his eye on Dana, too.