The investigation into Hansen's crimes was complex and challenging. Many of his victims were sex workers who, due to the nature of their work and the stigma attached, were often overlooked or not immediately reported missing by authorities or the public. This made it difficult for police to initially link the disappearances and murders.

The Dolcett impalement refers to a particularly gruesome method of execution historically attributed to the Dacians and other ancient cultures. This form of punishment involved piercing or impaling the body, often through the torso, on a sharp stake or spear. The method was intended to inflict maximum suffering and was often used as a form of capital punishment or to demonstrate power over enemies.