Levi Boone Helm was born on January 28, 1828, in Lincoln County, Kentucky. He was born into a family that was seen as honest and hard-working. When he was a young boy, his family moved to Jackson Township in Monroe County, Missouri. Helm grew up showing off his strength and skills. He liked to perform tricks, like throwing his Bowie knife into the ground and then retrieving it while riding a horse at full speed.

As he grew older, Helm became known for his rebellious nature. He once demonstrated his disregard for authority by refusing to listen to a sheriff's attempt to arrest him. Instead, he rode his horse up the stairs of a courthouse and into the courtroom while it was in session, causing a scene and shouting at the judge.

In 1851, Helm married a 17-year-old named Lucinda Frances Browning in Monroe County, Missouri. They had a daughter named Lucy. However, their marriage was troubled. Helm started drinking heavily. He would often ride his horse into their home and engage in violent behavior towards his wife. This violence became so severe that Lucinda filed for divorce. Helm’s father had to pay for the divorce, which damaged the family’s reputation. After this, Helm decided to go to California to seek gold and a new start.

Levi Boone Helm's criminal story is marked by violence and cannibalism. His journey to California began when he asked his cousin, Littlebury Shoot, to join him. When Shoot tried to back out, Helm killed him by stabbing him in the chest. After committing the murder, Helm traveled west alone. His actions caught up with him, and he was eventually captured and convicted of murder. However, he ended up in a mental asylum. Helm managed to escape after convincing his guard to take him for walks in the woods.

Once free, Helm headed west again and killed several men in different confrontations. He later teamed up with six other men where he admitted to having eaten parts of his victims. During one journey, an attack forced them into the wilderness. Lacking food, they killed their horses for meat, and Helm ended up eating one of his companions, Burton, after Burton died by suicide.

Helm continued his violent path after reaching San Francisco, where he murdered a rancher who had shown him kindness. He moved to Oregon and continued robbing and killing people. In 1862, after heavy drinking, Helm shot an unarmed man named Dutch Fred in a saloon. He also ate another fugitive who was with him at the time. When authorities captured him, his brother, "Old Tex," helped him avoid conviction by paying off witnesses. Helm was released and moved to Texas.

Helm's criminal activity persisted, and he returned to his violent ways, killing more men. He was finally apprehended in Montana alongside a gang led by Henry Plummer. During a secret trial, Helm lied to protect himself, accusing a friend of his own crimes. On January 14, 1864, the Montana Vigilantes executed Helm and others by hanging in front of a large crowd. Just before his execution, he reportedly exclaimed support for his principle. He jumped off the hangman's box before it could be kicked away, marking the end of his life. Helm was buried in Boot Hill cemetery in Virginia City.