Witch-trials looked for evidence to prove that a person was a witch. Evidence included such things as signs of plant medicine, or images of non-Christian gods. One way to physically test if a person was a witch was to 'swim a witch'. This meant they would throw them in a river with their hands tied. If they sank, they were innocent. If they floated, they were guilty of witchcraft and were hanged. This violent practice was not based on any actual evidence. Instead, it allowed the witch-hunter to look right and powerful for the scared people who were watching.