1 / 7I Know You Did It by Sue Wallman
I Know You Did It by Sue Wallman is a young adult thriller about Ruby, who starts at a new school and finds a note accusing her of a past secret. When students are found dead, the story turns to suspicion, possible framing and the danger Ruby may face.
At a glance
- Ruby finds an accusatory note in her locker on her first day at a new school.
- The plot centres on a death from Ruby's early childhood and two students later found dead.
- Listed as a winner of the Grampian Children's Book Award 2021.
Reference price: £9.99
Price checked: 12 Nov 2026
View offerAhead of Black FridayExplore the selectionOften bought together
Pros and cons
Pros
- A school-set mystery combines a protagonist's hidden past with a possible attempt to frame her.
- Customer feedback highlights plot twists, surprises, complex characters and engaging writing.
Technical specifications
11 specifications| Author | Sue Wallman |
|---|---|
| Publisher | Scholastic |
| Publication date | 6 May 2021 |
| Edition | 1st |
| Language | English |
| Print length | 352 pages |
| Reading age | 11 - 16 years, from customers |
| ISBN-10 | 0702302708 |
| ISBN-13 | 978-0702302701 |
| Weight listed | 250 g |
|---|---|
| Dimensions | 14.3 x 2.3 x 18.1 cm |
Who is it for?
A good fit for
- Readers looking for a young adult school-set crime thriller with secrets and murder-mystery elements.
- Fans of twist-led teen mysteries and suspense involving an unreliable position of suspicion.
Less suited to
- Readers seeking a light or non-threatening school story, as the plot involves deaths and a murder investigation.
Customer reviews on Amazon
- 5 stars
62% 62% - 4 stars
24% 24% - 3 stars
10% 10% - 2 stars
2% 2% - 1 star
2% 2%
Customer feedback describes the book as engaging, with a strong plot twist, surprises, complex characters and skilful writing. Pacing opinions are mixed: some readers say they finished quickly, while others found it slow. That contrast matters for readers choosing a fast-moving thriller, since the listing's fast-paced wording does not reflect every reported experience.
Positive themes
- Customer feedback praises the plot twists and surprises.
- Readers describe the characters as complex and believable and the writing as skilful.
Mixed feedback
- Pacing feedback differs. Some report finishing the book in under a day, while others find it slow-paced.
Frequently asked questions
What is I Know You Did It about?
Ruby finds a note accusing her of a secret on her first day at a new school. When students are found dead, she fears she is being framed or may be next.
Who wrote I Know You Did It?
The book is by Sue Wallman, author of Lying About Last Summer and Dead Popular.
How long is the book?
The listing gives a print length of 352 pages.
What age range is listed?
The listing gives a reading age of 11–16 years and attributes that guidance to customers.
Alternative options
The Cousins: A twisty, explosive YA thriller from the bestselling author of One of Us is Lying
£6.99
The Girl in Cabin 13: 1 (Emma Griffin® FBI Mystery)
£10.99
Murder on the Titanic
£7.99
Not Now, Bernard
£7.25
The Way I Used to Be: The TikTok sensation
£8.15
The Killer Isn’t™ Alice: The Bestselling Interactive Murder Mystery Puzzle Book - 46,600 Suspects, 1 Killer. Can You Solve the Crime? (The Killer Isn’t™ series, 1)
£7.49
A Good Girl's Guide to Murder: THE EXCLUSIVE AFTER DARK CRIME EDITION OF THE NO.1 BESTSELLING YOUNG ADULT THRILLER, NOW ON NETFLIX – NEW FOR 2026!: Book 1 (A Good Girl’s Guide to Murder – After Dark)
£10.29
Lying About Last Summer - a summer camp teen thriller for fans of We Were Liars
£7.32
The Cheerleaders: A dark and twisty thriller that will leave you breathless: 1
£7.69
Sister, Missing: Volume 1
£7.65
This Lie Will Kill You
£7.85
Lessons in Death: A thrilling murder-mystery perfect for teens: Volume 1 (Murder Academy)
£7.09
