Flashback by Iris Johansen

Kendra Michaels uses her heightened powers of deduction to draw out a serial killer who has not been seen or heard from in over fifteen years.
Chloe and Sloane Morgan were only children when their mother was the second victim of the Bayside Strangler. Now, after spending fifteen years trying to discover his identity, the sisters have suddenly vanished. Were they getting too close to the truth? The police consider their interest in the crime to be just a coincidence and have little motivation to pursue the cold case.
Armed with the box of photos, videos, police reports, and notes gathered by the sisters over the years—plus the extraordinary senses from being blind before recovering her sight via a revolutionary surgical procedure—Kendra follows the sisters’ trail of clues. Little does she realize that her search is about to unleash a long-dormant killer on San Diego. With help from government agent-for-hire Adam Lynch and private eye Jessie Mercado, Kendra must race to discover the identity of an infamous killer, not only to save the lives of the two sisters but also untold others.