Unknown Killers

Nikita Casap is an American convicted double murderer who killed his mother, Tatiana Casap, and his stepfather, Donald Mayer, at their home in Waukesha, Wisconsin, in February 2025. Prosecutors established that the killings were committed to obtain money, weapons and independence to carry out a planned assassination of U.S. President Donald Trump using an explosive-laden drone. Casap pleaded guilty to two counts of first-degree intentional homicide and, in March 2026, was sentenced to life imprisonment without the possibility of parole.

Nikolas Jacob Cruz became one of the most notorious mass killers in modern American history after carrying out the February 14, 2018, shooting at Marjory Stoneman Douglas High School in Parkland, Florida. Armed with a semi-automatic rifle, Cruz murdered 17 students and staff members and wounded 17 others before fleeing the campus, making it one of the deadliest school shootings in United States history. The massacre shocked the world and sparked an unprecedented movement led by student survivors demanding stronger gun laws and improved school safety. Cruz's history of behavioral problems, mental health concerns, online threats, and numerous contacts with law enforcement became central to public debate following the attack. The shooting permanently changed the national conversation surrounding school violence and mass shootings.

Obdulia Sanchez became the subject of international attention after livestreaming a 2017 DUI crash that killed her 14-year-old sister, Jacqueline Sanchez, in Los Banos, California. Prosecutors alleged Sanchez had been driving under the influence at high speed when she lost control of the vehicle, resulting in Jacqueline's death and serious injuries to another passenger. After serving time in custody and being released, Sanchez was fatally shot in a drive-by shooting in Stockton, California, in December 2025.

Paul Charles Denyer became one of Australia's most infamous serial killers after murdering three young women in Melbourne's bayside suburb of Frankston between June and July 1993. His crimes created widespread fear throughout Victoria, leading to one of the state's largest homicide investigations. Following his arrest, Denyer pleaded guilty to the murders and was sentenced to life imprisonment with a non-parole period. He remains incarcerated and is one of Australia's most notorious convicted serial killers.

Pedro López became one of the deadliest serial killers in modern history after confessing to the murders of hundreds of young girls across Colombia, Ecuador and Peru during the 1970s and 1980s. Nicknamed “The Monster of the Andes,” López terrorized vulnerable communities throughout South America by targeting poor and isolated children, many of whom disappeared without immediate investigation. His crimes shocked the world not only because of the staggering number of alleged victims, but also because López appeared calm and cooperative while confessing to investigators. Despite claiming responsibility for hundreds of murders, he ultimately served a relatively short prison sentence before disappearing after his release, creating ongoing fear and controversy surrounding his whereabouts and possible later crimes.

Robert Austin Sullivan was convicted of murdering Donald Schmidt, the manager of a Howard Johnson's restaurant in Homestead, Florida, during a robbery in April 1973. Sullivan and accomplice Reid McLaughlin abducted Schmidt, bound him and drove him to a remote area, where he was shot twice in the head with a shotgun. Sullivan initially confessed to the murder before later recanting and maintaining his innocence. Convicted of first-degree murder and robbery, he was sentenced to death and spent ten years on Florida's death row. Despite numerous appeals and pleas for clemency, including an intervention by Pope John Paul II, Sullivan was executed by electrocution at Florida State Prison on November 30, 1983.

Robert Black was a Scottish serial killer and paedophile convicted of the kidnapping, rape, and murder of four girls aged 5 to 11 in the United Kingdom between 1981 and 1986. As a long-distance delivery driver, he exploited his mobility to abduct victims from different regions, subjecting them to horrific sexual assaults before killing them and disposing of their bodies far from the abduction sites.

Robert Black Farmer became one of Australia’s most notorious child killers after the 2008 murder of 18-year-old Lauren Huxley on the Gold Coast, Queensland. Prosecutors alleged Farmer abducted Lauren as she walked home from a night out before sexually assaulting and murdering her, triggering one of the largest and most publicized homicide investigations in Queensland history. The case generated national outrage because of Lauren’s age, the predatory nature of the attack, and the extensive manhunt that followed. Investigators later uncovered forensic evidence linking Farmer to the crime, while media coverage focused heavily on his criminal history and escalating pattern of sexual offending. The murder remains one of the most infamous stranger-abduction killings in modern Australian criminal history.