A Blueprint for Murder

Whitney Cameron is in a quandary: he's attracted to his beautiful sister-in-law, Lynn, but also harbors serious suspicions about her. Her husband, Cameron's brother, died under mysterious circumstances, and now that the death of her stepchild, Polly, has been attributed to poisoning, he suspects that Lynn is after his late brother's estate, and killing everyone in her way.

• 
  Joseph Cotten

  Whitney 'Cam' Cameron
• 
  Jean Peters

  Lynn Cameron
• 
  Gary Merrill

  Fred Sargent
• 
  Catherine McLeod

  Maggie Sargent
• 
  Jack Kruschen

  Detective Lieutenant Harold Y. Cole
• 
  Barney Phillips

  Detective Captain Pringle
• 
  Harry Carter

  Wheeler (Uncredited)
• 
  Ed Hinton

  Ed (Uncredited)
• 
  Mae Marsh

  Anna Swenson (Uncredited)
• 
  Carleton Young

  Frank Connelly (Uncredited)