Henry "Hank/Boomer" Boyd
Fourteen-year-old Henry "Boomer" Boyd is known on the world wide web as the host of Forensics 411. Because of his  intelligence and passion for forensic science, Boomer is widely misunderstood and disliked by his peers. Since starting his blog and web show about crime and forensics back in sixth grade, the kids at school have called him Forensic Freak along with a handful of other cruel names. When a new girl who knows nothing about his jaded past moves to town on the first day of summer vacation, Boomer sees the chance to reinvent himself and claim the new girl as a friend. (His first in a long time.)He begins by changing his name to Hank. His next step is to force himself to make eye contact. If he can do that, his shrink says that everything else may very well fall in line.
Hannah Simmons
Hannah moves to Vista Point, North Carolina on the last day of eighth grade. After overhearing her parents' whispers, Hannah suspects that her new home has a secret. She turns to an online crime enthusiast to help her uncover the truth about her new home. Imagine her surprise when she learns that the forensic specialist is the weird  boomerang-throwing kid who lives just up the street. 

Chaucer 

Chaucer is Boomer's three-year-old bloodhound. Before Hannah moved to town, Chaucer was Boomer's only friend. But he grows just as fond of Hannah as he is of Boomer. The three are inseparable until Chaucer gets lost on an uninhabited island off the coast of Vista Point. He brings Hank and Hannah closer to finding out the truth about Stacy McFarland.

Chester Buckley

The chief of the Vista Point Police Department and brother of Vista Point's mayor, he is a member of the wealthy Buckley family. Chief Buckley seems determined to prevent Hannah and Boomer from learning the truth about what happened at Hannah's house decades ago. 

 

Dillon Buckley

Fourteen-year-old Mr. Popularity has hated Hank Boyd since the day Hank (known as Boomer back then) accidentally knocked Dillon unconscious with his boomerang in first grade. Ever since, Dillon has made it his personal mission to make Hank's life miserable. He is the grandson of the mayor of Vista Point and the great-nephew of the police chief.

Grandpa Boyd

Hank's maternal grandfather is the closest thing to a father that Hank has ever had. Hank and his mom, Angela Boyd, live with Grandpa on Bending Oak Drive. Though Grandpa suffers from dementia, he is still able to help Boomer and Hannah  uncover the truth about the disappearance of a sixteen-year-old girl who used to live in Hannah's house, but mysteriously vanished in 1985.