Samantha Alexander is one of the main characters in the series.
As a child, Samantha was often singled out for being different. Unwilling to back down from bullying, she learned to defend herself. When the bullies moved on to easier targets, Samantha defended those kids as well. She was never able to look away when someone needed help.
Her decision to enter the police academy was natural, and came as no surprise to her family. Police officers help people, and that's what Samantha wanted to do. She is one of the officers responsible for bringing Nathaniel Arkady into custody, and as a favor to her mentor, Detective Waters, she attends his execution in Ashcroft. On that day, she is chosen by the Messengers and is witness to the hidden evils of Ashcroft Penitentiary.