Characters

• Peter Houghton: The offender who shot and killed people and injured nineteen at his school, Sterling High.
  
• Josie Cormier: Peter's ex-best friend and Matt's current girlfriend.
• Alex Cormier: Josie's mother and Patrick's love interest. She is a judge at the Superior court in Grafton County.
• Patrick Ducharme: Detective on the Sterling Police Force and Alex's love interest (a recurring character in Picoult's novels.)
  
• Lacy Houghton: Peter's mother. A midwife. Used to be Alex Cormier's good friend.
• Lewis Houghton: Peter's Father. A happiness critic and college lecturer.
• Matt Royston: Josie's boyfriend. A jock. A bully.
• Jordan McAfee: Peter's defense attorney (a recurring character in Picoult's novels.)
• Selena McAfee: Jordan's wife who assists with her husband's case
• Drew: One of the popular kids who was only wounded in the shooting.
• Brady: Another popular kid who dated Courtney.
• Derek: Peter's only friend after Josie leaves him for the popular crowd.
• Mr. McCabe: A closeted gay teacher who ends up dying during the shooting.
• Joey: Peter's dead brother.
• Logan: Josie's biological father.

Victims

In order of death,

• Maddie Shaw: Josie's friend and a popular student.
• Courtney Ignatio: Josie's friend and a popular student.
• Whit Obermeyer: Alex's old boss.
  
• Topher McPhee: The school's pot dealer.
• Grace Murtaugh: Daughter of the town's minister.
• Kaitlyn Harvey: A freshman with special needs.
• Edward McCabe: The only teacher killed and Peter's former math teacher. He is gay.
• Noah James: Senior and a jock.
• Matt Royston: A popular jock, Josie's hot boyfriend. Most boys want to be him.