The character, made famous by Dame Helen Mirren in TV series Prime Suspect, will feature in a new novel which will be a prequel to those stories.
La Plante said she also plans to adapt the book, called 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 my books and TV series, Prime Suspect, portrayed brilliantly by Helen Mirren.
"But nobody knows what drove her to become a DCI or want to join the police force in the first place. When you first meet her in the early 90s, she is a very complex character, but what made her so?
"I can't say too much now, but readers will find out next year when the book is published; or in 2016, which is the 25th anniversary of Prime Suspect, when they watch Tennison the series."
Dame Helen, was given a Bafta Fellowship on Sunday night, said the Prime Suspect role was the one she was most "grateful" for because it taught her "how to act in film".