Blood Work is the seventh novel written by Michael Connelly, and the first to feature FBI criminal profiler Terry McCaleb. The book was published in 1998, and won the 1999 Anthony Award, the 1999 Macavity Award, and the 1999 International Grand Prix. The novel was also nominated for the Honkaku Mystery Grand Prize for Best Foreign Mystery of the Decade, but lost to Jack Kerley's The Death Collectors.
Within the continuity of Connelly's fictional Los Angeles, the book was a nonfiction account of McCaleb's investigation that was ostensibly written by journalist Keisha Russell.
"Blood work" as a concept carries multiple meanings. For Terry McCaleb it refers to his work as a profiler with the FBI, trying to catch serial killers. It also refers to the work of criminologists who analyze blood and DNA. For murders and other violent criminals it may mean a blood debt that must be repaid in blood. In the medical context, it describes both the routine drawing of blood for analysis, as well as surgery, organ transplants, transfusions, and the blood typing that must accompany these.
- Terry McCaleb later reappeared in the Harry Bosch novel A Darkness More Than Night.
- Keisha Russell, who first appeared in The Last Coyote and later appears in Lost Light, Angels Flight, The Narrows and The Scarecrow, appeared in Blood Work and ostensibly wrote the book as a nonfiction work.
- Gilbert Spencer later reappeared in Angels Flight.
- Jaye Winston, Graciela Rivers, and Raymond Torres later reappeared in A Darkness More Than Night, and Graciela appeared again in The Narrows.
- Harry Bosch's father is mentioned when Jaye Winston suggests that Terry hires Mickey Haller. Mickey later makes his debut in The Lincoln Lawyer.