The Wright 3
The London Eye Mystery
Walls Within Walls
The Mysterious Benedict Society
From the Mixed-Up Files of Mrs. Basil E. Frankweiler
The Westing Game
Books that are not ideal choices for this report.
Not Traditional Mysteries
When You Reach Me
Liar and Spy
The Fourth Stall (Go Cubbies!)
More Fantasy Style Mysteries
The House with the Clock in Its Walls
The Sixty Eight Rooms
Mysteries can be hard to choose. Your local library or book store may be more help than just looking on Amazon. Please note that Encyclopedia Brown books have stories that are too short for this assignment.
Good online list, but some of these are a little young for fifth grade.