A Long Cold Fall - The Cooper MacLeish series, #1

First published in 1991, Sam Reaves's debut novel features Chicago taxi driver Cooper MacLeish, a Vietnam veteran with a philosophical bent and a stubborn reluctance to let bad guys get away with things. When he reads of the apparent suicide of Vivian Horstmann, whom he once loved, Cooper finds himself drawn into the drama of an unhappy family as he tracks down Vivian's runaway son, who insists that her death was no suicide. Drama escalates to crisis as it becomes clear that somebody wants the boy as dead as his mother; Cooper will need all the rock-hard toughness he brought out of the A Shau valley to keep the boy alive and uncover the truth about Vivian's death.