Who is LIeutenant Joe Leaphorn from Talking God and what is their importance?

LIeutenant Joe Leaphorn is one of the two main characters, Lieutenant Joe Leaphorn is a recurring detective in Tony Hillerman's novels. Leaphorn is middle-aged, and his beloved wife Emma has recently died. Leaphorn is grief-stricken, has lost weight and often finds himself talking aloud to Emma in their home. He uses vacation time to investigate a crime in Washington, DC because he cannot face the prospect of going on vacation alone.