News on Relevant Science: History's 10 Most Famous Criminal Duos

Some criminals like to work alone, while others need an accomplice to carry out their illegal acts. Criminal duos are determined to make their sadistic fantasies a reality, and it’s all the more possible with the help of a partner. Check out history’s 10 most famous criminal duos.

Dick Hickock and Perry Smith

Together, Dick Hickock and Perry Smith murdered the Clutter family and were the central characters in Truman Capote’s classic non-fiction novel, In Cold Blood. On Nov. 15, 1959, the two ex-convicts raided the Clutter family farmhouse in Holcomb, Kan., in search of a safe containing $10,000. They never found a safe and decided to kill the four family members one by one. Smith admitted to shooting the father and son, but neither one admitted to killing the two women. Hickock insisted that Smith performed all the murders, and after a great deal of story revisions, Smith finally confessed to shooting all of the Clutters. Smith and Hickock were discovered in Las Vegas and taken into custody in December 1959. The men were sentenced to death and executed by hanging on April 14, 1965.
Bonnie and Clyde

Bonnie Parker and Clyde Champion Barrow are arguably the most well-known American outlaws, who carried out one of the biggest crime sprees in U.S. history. The gun-toting couple and their gang traveled throughout the central United States, robbing dozens of banks, stores, and gas stations during the Great Depression. The lovers garnered national attention for their criminal activities that always seemed to outsmart police. Although Bonnie rode with Barrow and the gang for several years, there is no record of her ever shooting a gun or murdering anyone. Clyde and the gang reportedly killed nine police officers and several civilians. Authorities finally caught up to Bonnie and Clyde on May 23, 1934, when they ambushed the outlaws on a rural road in Bienville Parish, La., killing them instantly.
The Menendez brothers

In 1989, brothers Lyle and Erik Menendez shot their parents to death at their Beverly Hills home. The murderous duo carefully planned the attack to get rid of their strict father and end their mother’s agony. On the night of the murders, the Menendez brothers returned home to the mansion and shot their father in the back of the head and gunned down their mother. They dumped their shotguns and bought movie tickets to use as an alibi. Lyle called that night to report that his parents had been killed. The Menendez brothers began spending their inheritance money on lavish items and started fake businesses, raising suspicions that they were somehow involved in their parents’ murders. Erik eventually confessed to his psychologist about the murders, and the brothers were taken into custody. The Menendez brothers were convicted of two counts of first-degree murder and conspiracy to commit murder. They were sentenced to life in prison without the possibility of parole.
The Columbine Killers

Eric Harris and Dylan Klebold were the disturbed teenagers responsible for the Columbine High School massacre on April 20, 1999. On that chilling day, the two high school seniors went on a shooting spree inside their suburban school, killing 13 people and injuring 24 others before turning the gun on themselves. Journal entries revealed that Harris and Klebold’s attack was designed to be a terrorist bombing that would kill everyone inside the school, but when their homemade bombs fizzled, the boys began shooting instead. Years after the tragic incident, researchers have discovered that Harris and Klebold hadn’t been bullied, but actually bullied others and had serious psychological problems, including depression, paranoia, and suicidal tendencies.
Robert Thompson and Jon Venables

Robert Thompson and Jon Venables are two of the youngest murderers in history. In 1993, the 10-year-olds abducted and murdered two-year-old James Bulger in Liverpool, England. The young boys lured the toddler away from a shopping mall when his mother was inside a store, and took him on a long walk across Liverpool to a railway line, where they tortured and beat him to death. Bulger suffered several blows to the head and was sexually abused by Thompson and Venables. The vicious boys left Bulger’s mutilated body on the railroad tracks to be cut in half. Police identified the two boys from mall videotapes, and later matched blood found on their shoes to Bulger. Thompson and Venables were arrested and tried in an adult court, where they were both found guilty of murder and sentenced to detainment indefinitely.
Nathan Leopold and Richard Loeb

From the outside, Richard Loeb and Nathan Leopold didn’t meet the profile of cold-blooded killers, but the murdering duo proved to be just that. Eighteen-year-old Loeb and his well-educated lover, 19-year-old Nathan Leopold, wanted to know what it felt like to kill someone, and that someone happened to be Loeb’s cousin, Bobby Franks. On May 21, 1924, the duo kidnapped and murdered 14-year-old Franks and dumped his body in a drain near their homes in Chicago. It seemed like a flawless killing to the men, but Leopold accidentally left his glasses at the crime scene. The men were taken into custody and confessed to the murder 10 days after the incident. Loeb and Leopold’s trial didn’t play to their favor, except that they escaped the death penalty. Loeb was killed in prison by a fellow inmate, and Leopold was released in 1958 and moved to Puerto Rico.
DC Snipers

The DC snipers, John Muhammad, 41, and John Lee Malvo, 17, were the duo responsible for shooting and killing 13 people from Washington D.C., to Rockville, Md., and Fredericksburg, Va. The DC snipers’ killing rampage lasted three weeks during October 2002. Muhammad and Malvo traveled on the Capital Beltway, causing mass fear in communities along the way, but always staying ahead of law enforcement. During their shooting sprees, the men would communicate via two-way radios and alternate between shooter and lookout man. Muhammad and Malvo were eventually found sleeping in their car at a rest stop and taken into custody for federal weapons charges. The murdering duo received life terms in prison, without the possibility of parole. Muhammad was sentenced to death and Malvo was sentenced to life in prison.
Frank and Jesse James

Frank and Jesse James are the notorious outlaws of the Wild West. The James brothers were Confederate guerrillas in the Civil War, where they engaged in a wide range of criminal activity. The men held up and robbed trains, killing 22 of the 23 Union soldiers on board and scalping many of them. Following the war, Frank and Jesse started robbing banks, trains, and shops around Iowa, Alabama, and Texas. In 1866, the dangerous duo pulled off the very first daytime bank robbery, where they killed a bystander and stole $58,000. The American outlaws’ crime spree came to an end when Jesse was killed by gang member Robert Ford.
The Lonely Hearts Killers

Raymond Fernandez and Martha Beck are the infamous Lonely Hearts Killers, who teamed up to woo lonely, single women and subsequently rob and even kill the ones who fell for their scam. Using Fernandez’s theft experience, the duo began targeting single women by writing letters to wanted ads. He would woo them, then take their money and run. It wasn’t long before Beck grew jealous of Fernandez’s conquests and the couple decided to start killing their victims, as well. Following the murder of a widow and her child, Fernandez and Beck were arrested and convicted of nearly 20 murders. In 1951, the couple was executed by electric chair.
Butch Cassidy and the Sundance Kid

Butch Cassidy was a notorious Old West outlaw who had a talent for robbing trains and banks. Between 1896 and the early 1900s, Cassidy and his accomplice Harry Longabaugh, better known as the "Sundance Kid," held up dozens of trains, robbed passengers, and broke into safes, collecting thousands of dollars. The duo and other members from their gang, the Wild Bunch, took up more robbery activities, including the infamous Union Pacific overland flyer robbery that lead to a serious man hunt. With authorities on the lookout, Cassidy and Sundance escaped to South America, where the duo was allegedly killed in a shootout.