The Toolbox Killers were Lawrence Bittaker and Roy Norris, a duo of American serial killers active in 1979. They gained infamy for abducting, torturing, and murdering five teenage girls in Southern California. Their name comes from the use of tools, such as pliers and hammers, to carry out brutal torture on their victims. The pair recorded audio of their horrific acts, further adding to the gruesome nature of their crimes. Bittaker was sentenced to death and died in 2019, while Norris received life in prison without parole. Their case remains one of the most chilling in U.S. criminal history.

Kouri Richins, a Utah mother of three, was charged with the murder of her husband, Eric Richins, in 2022. Authorities allege that Kouri poisoned Eric with a fatal dose of fentanyl, motivated by financial struggles and life insurance policies. Prior to her arrest, Kouri wrote a children's book about grief, which added a bizarre twist to the case. Investigations revealed a history of suspicious behavior, including an affair and an earlier attempt to poison Eric. Kouri's trial has gained significant media attention due to its strange and chilling elements​

On November 30, 2021, 15-year-old Ethan Crumbley opened fire at Oxford High School in Michigan, killing four students—Madisyn Baldwin, Tate Myre, Hana St. Juliana, and Justin Shilling—and wounding seven others. Crumbley used a 9mm handgun that his father had purchased days before. His disturbing behavior was noticed by school staff before the shooting, but no immediate action was taken. Crumbley pleaded guilty to multiple charges, including murder and terrorism. His parents were also charged with involuntary manslaughter for failing to secure the firearm and address his mental health concerns​.

Mark Winger, a nuclear engineer from Springfield, Illinois, was convicted of the 1995 murders of his wife, Donnah Winger, and Roger Harrington, a shuttle driver. Initially, Winger claimed he shot Harrington in self-defense after Harrington attacked Donnah with a hammer. The case was closed as justifiable homicide. However, four years later, new evidence, including phone records and testimony from Winger's lover, revealed that Winger had lured Harrington to his home and staged the crime to cover up his wife's murder. He was sentenced to life in prison in 2002