Complex sentence: One notable case in Petrosino's stint with the Italian Squad was when the Italian tenor Enrico Caruso, who was performing at the Metropolitan Opera House in New York City, was being blackmailed by Black Hand gangsters who demanded money in exchange for his life.
Split into simpler sentences: One notable case in Petrosino's stint with the Italian Squad involved the Italian tenor Enrico Caruso, who was performing at the Metropolitan Opera House in New York City. He was being blackmailed by Black Hand gangsters who demanded money in exchange for his life.