Jane Tennison, made famous by Dame Helen Mirren, will feature in the new novel and La Plante said she also planned to adapt the book, Tennison, for TV.
She said: "I am extremely excited to have begun work on the Tennison project. Jane Tennison is a character who millions of people know and admire from Prime Suspect.
But nobody knows what drove her to become a DCI or want to join the police force in the first place. When you meet her in the early 90s, she is a complex character, but what made her so?
"I can't say too much now, but readers will find out when the book is published; or in 2016 when they watch Tennison the series."