Complex sentence: Nearly a year after her disappearance, police agreed to work with the Penn State Paranormal Research Society, who in turn called in Carla Baron, a psychic who was later involved in the Elizabeth Smart kidnapping investigation.
Split into simpler sentences: Nearly a year after her disappearance, police agreed to work with the Penn State Paranormal Research Society. PRS called in Carla Baron, a psychic who was later involved in the Elizabeth Smart kidnapping investigation.