The script held in the Crawford Collection in the AFI Research Collection contains the following character notes (excluding regular characters):
'WENDY SHERLOCK (16) Wendy is a "little raver" ... very attractive, very sweet, unusually intelligent. Her parents suspect she's a raving psychopath, and have kept her caged in the garage for over a year. They are proven to be correct.
'MR. SHERLOCK: (Late 30's) Wendy's father. He's lived with a terrible secret for over ten years, and the stress shows in his appearance and his manner. A man on the verge of nervous collapse. Is an unsuccessful artist - tends to be a little trendy - but is not arty.
'MRS SHERLOCK: Wendy's mother. Like Mr. Sherlock, she's at her wit's end. Believes that her daughter is a genetic monster. Intelligent - good educational background
'POLICEWOMAN: Jane Bell. Established character. In this story, she's caught between her intuitions as a woman and the cool logic required of a good policewoman.
'TONY LATIMER: (18) Skin-head (or rough). Victim of a macabre slashing.
'WALLY: (18) Skin-head (or rough). Tony's mate.
'DOCTOR: One scene only, but fairly heavy dialogue.
'MATRON: In charge of the girls at the Social Welfare Department.
'RITA: (16) An attractive girl at Social Welfare.
'NEIGHBOUR LADY: Lives next door to Sherlocks. Little dialogue. Comic role.
'GIRL: One scene only. No dialogue.'