O'Brien/Anderson Books in Order

The O'Brien/Anderson books move from courtrooms to the streets of Los Angeles, and they do it with a very different rhythm. These are police procedurals built around Detective Finn O'Brien and Detective Cori Anderson, two investigators who know the city from the inside out and know that every crime scene comes with layers of class, race, politics, and personal history. The first book, Severed Relations, makes that clear right away.

Finn is an Irish immigrant who came to the United States as a teenager. He carries the weight of two cultures, the memory of his brother's death, and a strong personal code that has made him unpopular inside his own department. Cori is tough, practical, deeply loyal, and balancing police work with a complicated family life. Together they are smart, stubborn, and not especially good at looking away.

That is usually the problem.

The cases in this series start with shocking murders, but they quickly widen into something messier. A wealthy household massacre. A dead woman on a freeway. Young undocumented men disappearing from Los Angeles. A killing inside an artists' colony. A plane explosion with old ties to Finn's past. Each mystery pulls the pair into a different corner of the city and shows how power protects itself when money, status, or institutions are involved.

Los Angeles matters here. Not just as backdrop, but as a patchwork of neighborhoods, loyalties, and hidden worlds. The books move from elite homes to overlooked communities, from political pressure to family secrets, from street-level policing to forces that would rather bury the truth. Rebecca Forster uses those shifts well. The city feels big, crowded, and divided, but never generic.

The ongoing tension comes from both the cases and the partnership. Finn is already a pariah in parts of the department, and Cori chooses to stand with him anyway. That choice has costs. Their investigations strain friendships, family ties, and their own sense of safety. At the same time, the books never lose sight of the people caught in the middle, especially the vulnerable people the system finds easiest to ignore.

If you like crime series that mix pace with conscience, this one is a good fit. The tone is gritty but not hopeless, emotional without getting soft, and sharp about the ways public institutions can fail. Read in order if you can. The murders may be separate, but Finn and Cori's trust, scars, and hard-earned bond build from book to book.