Deadly Inheritance

There are a number of inheritors to a fortune who are getting killed by a mysterious somebody whom we do not see. Each death is novel, but not terribly graphic. Who did it?

• 
  Tom Drake

  Inspector Greville
• 
  Femi Benussi

  Simone Marot
• 
  Ivo Garrani

  Leon
• 
  Ernesto Colli

  Janot
• 
  Valeria Ciangottini

  Colette Marot
• 
  Isarco Ravaioli

  Jules Didier
• 
  Giovanna Lenzi

  Rosalie
• 
  Andrea Fantasia

  Notaio
• 
  Alessandra Maravia

  Natalie
• 
  Silvano Spadaccino

  Camionista