Complex sentence: It was in the waiting room of Greystone Park Psychiatric Hospital in New Jersey that he met Allen Ginsberg, who was there after being admitted in 1949, after Ginsberg was arrested for having stolen goods in his apartment and the vehicle he was in.
Split into simpler sentences: It was in the waiting room of Greystone Park Psychiatric Hospital in New Jersey that he met Allen Ginsberg, who was there after being admitted in 1949. After Ginsberg was arrested for having stolen goods in his apartment and the vehicle he was in.