Director Alexandre Moors concentrates on the events leading up to those murders -- or, more precisely, on the warped relationship that spawned them. John (Isaiah Washington) increasingly takes control of Lee (Tequan Richmond), an abandoned young man he met in the Caribbean.
After a brief prologue that's set in Antigua, Lee joins John in Tacoma, Washington. There, the two forge a weird alliance in which John becomes an impromptu father figure to the impressionable Lee.
Under different circumstances John's approach might have made for a mutually satisfying relationship, but John, we soon learn, has enough anger and resentment to undermine any connections he might make.
Some of John's fury derives his belief that his former wife robbed him of rights involving his children. He sees himself as a victim, someone deprived of an essential part of his manhood. He thinks his fatherhood has been stolen.
For his part, Lee -- perhaps fearing another abandonment -- clings to John, following him on a path of violence that begins in Washington state and culminates in the area around D.C.
In Tacoma, John and Lee stay with one of John's old army buddies (Tim Blake Nelson) and his wife (Joey Lauren Adams). Nelson and Adams may not be portraying an ideal couple, but they represent the last contact with any sort of normalcy for John and Lee.
Washington's John is all the more dangerous because he's learned how to justify his cruelty. At one point, he leaves Lee tied to a tree in the woods, a test of the young man’s resourcefulness and determination that easily could have turned fatal. You get the impression that John believes he's acting in the young man's best interests by forcing him into such dubious character-building exercises.
Hindsight makes John seem like a lost cause, but we can imagine an alternative future for Lee had he not been so badly in need of a male authority figure. Too bad he found the wrong one.
Those familiar with the real-life events that inspired Blue Caprice (the title derives from the car that John buys and which is used in the killing rampage) know how the story concludes.
I don't know whether understanding John and Lee provides insight into the inner lives of the real killers, but Moors' spare and disturbing movie gives us a possible way to look at them -- should we choose to turn our attention in that direction at all.
By taking us deep into the world that John and Lee inhabit, Moors shows us how it’s possible for people to become totally absorbed in patterns that make sense only to them. Such isolation -- when abetted by the twisted logic of paranoia and hate -- too easily become a precondition for unspeakable crimes.