Alex Cormier
- Successful judge in Sterling, New Hampshire.
- Single mother of Josie Cormier.
- Disagrees with Josie's desire to meet her father, Logan Rourke.
- Originally assigned to be the judge of the Sterling High shooting case.
- Eventually taken off the case because the court lists Josie as a witness.
- Very close friend to Lacy Houghton.
Josie Cormier
- Daughter of Alex Cormier and Logan Rourke.
- Seventeen years old.
- Matt Royston's girlfriend.
- Peter Houghton's kindergarten best friend.
- Ends her friendship with Peter in middle school to join the popular group.
- Finds and visits her father only to be rejected by him.
- Hides in the locker room with Matt when Peter starts shooting, Matt dies next to her.
- Considers suicide after her release from the hospital but decides against it.
- Questioned multiple times by investigators.
- Eventually forced to testify at the court hearing for the shooting .
Peter Houghton
- Son of Lacy and Lewis Houghton.
- His brother, Joey Houghton, dies in a car crash.
- Seventeen years old.
- Josie Cormier's kindergarten best friend.
- Victimized by bullies his whole life.
- Creates a computer game with a setting modeled exactly like Sterling High School. The object of the game is to kill the popular kids.
- Circles his victims in a yearbook.
- Shoots ten people in Sterling High School after displaying a message on all school computers that says: "Ready or not, here I come."
- Is immediately taken to a correctional facility to await trial.
Lacy Houghton
- Mother of Peter and Joey Houghton.
- Wife of Lewis Houghton.
- Nurse and midwife.
- Doesn't understand the reasoning of Peter's actions.
- Testifies against Peter in his trial.
Matt Royston
- Seventeen years old.
- Josie Cormier's boyfriend.
- Plays for the hockey team at Sterling High School.
- Bullies Peter Houghton for many years.
- Killed in the Sterling High School shooting.
Patrick Ducharme
- Works as a detective for the Sterling Police Force.
- Head detective of the Sterling High shooting.
- Finds Peter Houghton in the locker room after the shooting and arrests him.
- Carries Josie, bleeding and unconscious, out of the school.
Jordan McAfee
- Peter Houghton's lawyer.
- Married to Selena McAfee.
- Has a newborn child named Sam.
- People of Sterling incessantly reprimand him for defending Peter in court.