Blood Test is the second novel by Jonathan Kellerman, published in 1986. It is told from the first-person point of view of Dr. Alex Delaware, a child psychologist who is Kellerman's main character in the majority of his novels. The novel also includes Delaware's best friend, LAPD Detective, Milo Sturgis. A secondary plot of the novel also involves Dr. Delaware's involvement in child custody cases as a consultant to family court.