Solution: The Theft During the Eclipse at the School

The clues

• 
  DarioThe jazz musician.

  He was on a chair.

• 
  BrunoThe cook who tastes everything.

  He was in the bottom row.

• 
  AlmaThe retired botanist.

  She was in the third column from the left.

• 
  LenaThe painter who never finishes a canvas.

  She was on a stool.

• 
  GretaThe gardener who talks to her roses.

  She was on a mat.

• 
  Theo · VictimThe paperboy.

  The victim. He was alone with the killer. He was not in a corner of the room.

• 
  IreneThe architect restoring the east wing.

  She was in the fourth row. She was not beside a desk.

Step by step

The order our solver finds. Each step uses only the clues and what the steps before it proved, and its heading links to the technique.

1. Last cell left Every other cell is ruled out for Lena, by her testimony or by a row or column already taken. Placed: Lena: row 6, column 5 (Head’s Office).
2. Pinned suspects Bruno can only be in the bottom row, so nobody else can be there.
3. Pinned suspects Irene can only be in the fourth row, so nobody else can be there.
4. Pinned suspects Alma can only be in the third column from the left, so nobody else can be there.
5. The only one who fits Only Bruno can still reach the right column, so he must be there. Placed: Bruno: row 7, column 7 (Playground).
6. Room counting The victim, Theo, cannot be in the highlighted cells: his room there could not hold exactly one other person. The cells meant: row 1, column 2; row 2, column 2; row 2, column 6; row 3, column 4.
7. Pinned suspects Theo can only be in the fifth row, so nobody else can be there. Placed: Dario: row 3, column 4 (Canteen); Greta: row 2, column 2 (Cloakroom); Alma: row 1, column 3 (Corridor).
8. Room counting The victim, Theo, cannot be in the highlighted cells: his room there could not hold exactly one other person. The cells meant: row 5, column 1. Placed: Theo: row 5, column 6 (Head’s Office); Irene: row 4, column 1 (Chapel).