Long Bright River

This novel by Liz Moore has two sisters at its core. One is a cop in Philadelphia and the other is an addict and prostitute in the same city. Raised by a perpetually angry grandmother after the death of their addicted mother and abandonment by their father, the girls were once so close that they could finish each other's sentences. But now, older sister Mickey is a patrol cop in the neighborhood where her sister turns tricks in order to get high. They haven't really spoken in years although Mickey tries to keep an eye out for younger sister Kacey. When Mickey gets a call about an unidentified body--female, same age as Kacey--she races to the scene. It's not Kacey, but Mickey starts hunting for her sister and finds out that no one has seen her in several months. As more bodies of young woman start appearing, Mickey's efforts to find her sister intensify and lead her to cross the line from professional to personal. When Mickey gets a lead from her sister's best friend on the streets that the serial killer may be a policeman, Mickey doesn't know who to trust.  When she's not working her demanding rotating shifts, she is a single mom, trying to raise a child without support from her family and relying on flaky babysitters.
The novel is gritty and atmospheric, creating a clear picture of Mickey's love-hate relationship with the working class neighborhood she patrols, Kensington. We also get inside her personal connections to those affected by the opioid epidemic that has been ravaging the country for the last several years.  Mickey is a sympathetic character in spite of her faults and occasionally impulsive and potentially reckless decisions.
A more detailed summary of the plot is provided at the New York Times. Maureen Corrigan calls this twisty crime novel "extraordinary" in her Washington Post review. The Guardian calls it a "family drama, history and social commentary wrapped up in the compelling format of a police procedural" and offers a bit of history on the author's research process.