Before She Knew Him by Peter Swanson

In Before She Knew Him, artist Hen and her husband Lloyd have just moved to the suburbs to get a new start after her recovery from a manic episode during which she became obsessed with the unsolved murder of a young man named Dustin Miller. When their new neighbors, Matthew and Mira, invite them over for dinner, Hen is shocked to see a trophy in Matthew’s office that was taken from the scene of Miller’s murder. Though Hen’s bipolar disorder is under control now, she still finds herself doubting what she’s seen. When she learns that Matthew is a teacher at the school Miller once attended, she begins to follow him to confirm her suspicions. She witnesses him committing another murder, but her history of paranoia means that neither her husband nor the police are willing to believe her.

This is a dark, fast-moving work of psychological suspense with a twisted, unpredictable plot that builds to a dramatic resolution. It reminded me a lot of something by Patricia Highsmith. If you’re interested in checking out any of Peter Swanson’s other books, I’d highly recommend The Kind Worth Killing.