In Dubus's "Killings," how is the title significant?

Andre Dubus's "Killings" is about two murders; therefore, the title is quite appropriate. First, Matt Fowler's son Frank is killed by Richard Strout; then, Fowler kills Strout to avenge his son and because of his and his wife's grief. The story is written from Matt Fowler's point of view and discusses the events that lead up to both killings. Fowler's view is limited to his son's perspective on the first killing; but the agonizing grief that leads Fowler to avenge his son's death is quite detailed. The effect of Frank's murder is assessed deeply because Richard killed him in front of his own two sons and his wife. Not only that, but Frank's parents and siblings are stricken with unfathomable grief that they never expected to feel.

Unfortunately, Matt and his wife's grief is intensified when Ruth sees Richard at the store one day. They had not thought about Richard getting out on bail and walking around the city a free man. After discussing this with his friend Willis, they plan to kill Richard to ease the pain and suffering as well as to get justice that might be limited through the court system. Finally, the last few pages of the short story detail the plan, the deception and the violence wrought on Richard during the last few hours of his life. In the end, Matt returns to his wife after killing Richard and resumes his life. Nothing is said as far as the consequences Matt must face after he kills Richard.