Complex sentence: The property, at the time, was owned by the man seen digging, who is now deceased, that was convicted of a rape six years after the disappearance and had later been convicted of a child's sexual assault in the 1960s.
Split into simpler sentences: The property, at the time, was owned by the man seen digging, who is now deceased. The man was convicted of a rape six years after the disappearance and had later been convicted of a child's sexual assault in the 1960s.