inhalt einer Novel korrigieren

Hallo,
könnt ihr bitte meinen text korrigieren?
danke!
The novel tells the story of a murder which happened 20 years ago.
The main character is Sheila who is married to Giles. They are well off and so they decide to have a home. Therefore Sheila should choose a house on her own because Giles is on a business trip. Sheila finds the perfect villa in Dillmouth. But as Sheila visits the villa it seems very known to her. She remembers the door that led from drawing –room to dining –room, the garden steps and even the wallpaper in the nursery. Then while she is standing on the stairs in the corridor she suddenly gets a vision in which she sees a dead person who she calls Helen. Sheila wants to know who was Helen and what had happened. After she had put an advertisement in lots of papers she meets people who knew Helen. Through this she finds out that Helen was her step mother. She wants to meet Lliy, the nurse but she get also strangled from the same murderer like Helen. The murder occurred in reality as Sheila was still a child. There are three suspicious persons. Later Sheila is nearly alone at home. The murderer appears again and wants to kill her. Fortunately, Miss Marple comes in the right moment and the murderer can be seized by the police.
Was heißt Hauptverdächtige auf englisch?