In addition to ghosts and poltergeists, Grosse also investigated numerous claims of precognition. He also put together an extensive collection of alleged examples of psychic photography. He continued this work right up until the summer of 2006.
In addition to ghosts and poltergeists, Grosse explored various claims of precognition. He amassed a substantial number of alleged examples of psychic photography. His work continued until the summer of 2006.