What are the motifs in The Assassination of Jesse James by the Coward Robert Ford by Ron Hansen?

The cost of crime is a recurring idea. Jesse James, the members of his gang and his friends and family pay for the crimes committed by Jesse, sometimes paying the ultimate price by giving their lives. Zerelda Samuels is an example of this theme. Jesse's mother is vocal about her disapproval of his lifestyle but says it's because her heart will be broken if Jesse is killed. She doesn't seem particularly upset by Jesse's criminal actions and provides him alibis on several occasions, but doesn't want him to die for his crimes.