After the murder of 15-year-old Milli Penn, Grand Rapids detectives investigate the masked shooter, rumored to be another teenager linked to a fight club; then, another shooting strikes and detectives must solve the case before more lives are lost.

After a gunfight, Jeremy Parnell is found dead. Detective Katie Roszkowski, leading her first homicide case, uncovers a party bus incident; with few witnesses, she must discover what happened when partiers left the bus and why it escalated to murder.

After a shooting, the detectives investigate a victim with a history of domestic complaints; as the victim fights for his life, the female shooter claims self-defense; her attempt to hide evidence raises doubts about her true motive.

What seemed like an accidental overdose becomes a murder investigation when a jail informant tips off Grand Rapids detectives; conflicting witness accounts leave the detectives searching for hard evidence to solve Dana's death.

After a gunfight outside a bar ends with two dead, Grand Rapids detectives discover that twin brothers are involved.

A bullet kills 15-year-old La'Kyijah Williams, outraging Chief Eric Winstrom; CCTV shows a masked gunman, but witnesses refuse to talk until a tip names a suspect; when officers arrest him at a traffic stop, detectives don't have enough evidence.