He was born on 10 February 1660 and ordained Schattenjäger on 14 April, 1678.
He was hired by mayor Crodwell of Charleston to solve a series of ritualistic murders. Against his father's wishes, he went to the American Colonies and brought the Talisman with him. The procedure reminded him of similar cases his Father saw in St. Dominique. As he was there in the expense of the community, Crodwell was pushing him in coming to a verdict and was not happy when Gunter told him that he needs to investigate. He was attracted to Eliza, a slave woman in the service of Crodwell, whom he sometimes abused sexually. Eliza seemed more brilliant and civilized than most of the townsfolk. She wished to know more about him and his land, and the two fell in love.
During his stay there, he fought against the fear of the people, the unfamilirity and inhorpitality of the environment and Crodwell's antipathy (his affection to Eliza being a reason).
While in The Crow's Nest tavern, he found out that all the victims were crew members on a certain slaving expedition to Africa. Using the name of a surviving member of the crew, living in the West Indies, he set a trap for the coven. He spread the rumor that he is returning to Charleston, and having arranged the protection of assistants, Gunter impersonated the sailor arriving at Charleston to be captured by the coven.
In the ritual, he was protected by the Talisman, which brought the lead witch back to her senses; she was Tetelo. It was then when his men showed up and attacked the slaves in the ritual, he urged her to run away. Tetelo's tribe was captured, and Gunter struggled with his feelings, while Tetelo asked for her evil father' spirit to release her from her duty and live a new life with Gunter.
Gunter was divided between his love and his duty and could not avoid betraying either of them. Seeking a sign from God in the wild, he heard the sound of a snake nearby. He threw his dagger only to see that he had killed a dove. It was then when he was notified that the witch was caught and she was ready to be burned at the stake.
Gunter attempted to save Tetelo but insisting to Crodwell that they deserve a trial in order to reveal more secrets, but Crodwell accused him for being seduced by her charms. Seeing her burning, and cursing the villagers, Gunter used the power of the Talisman to save herself, which, combined to that of her African gods, transformed her into an evil entity.
Tetelo felt that she and her feelings were betrayed by Gunter, who saved her only because of his guilt. The Talisman left him and went to Tetelo. He completed his journal and sent it back to his family, and himself sought to be lost in anonymity and be forgotten.
It is said that he died on 24 June, 1693.