Solution: The Lost Glove at the Museum

The clues

• 
  ZoeThe tattoo artist.

  She was in the Sculpture Hall with another woman.

• 
  YaraThe young pharmacist.

• 
  JonasThe shy librarian.

  He was in the fourth row.

• 
  VeraThe widow who sets the crosswords.

  She was in the Courtyard. She was in the sixth row.

• 
  IreneThe architect restoring the east wing.

  She was on a stool.

• 
  Paula · VictimThe opera singer between engagements.

  The victim. She was alone with the killer. She was beside a plant.

• 
  GretaThe gardener who talks to her roses.

  She was in the Archive.

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 Vera, by her testimony or by a row or column already taken. Placed: Vera: row 6, column 3 (Courtyard).
2. Pinned suspects Jonas can only be in the fourth row, so nobody else can be there.
3. Shared rows and columns Zoe, Irene, Paula and Greta can only be in the second column from the left, the fourth column from the left, the sixth column from the left and the right column between them, so nobody else can be in those columns.
4. Follow it to a contradiction If Jonas were in the highlighted cell, a room count would come out wrong. So he is not there. The cells meant: row 4, column 1. Placed: Jonas: row 4, column 5 (Workshop).
5. Follow it to a contradiction If Irene were in the highlighted cell, Greta would have no cell left. So she is not there. The cells meant: row 5, column 7. Placed: Irene: row 3, column 2 (Sculpture Hall); Zoe: row 2, column 4 (Sculpture Hall); Paula: row 7, column 6 (Workshop); Greta: row 5, column 7 (Archive); Yara: row 1, column 1 (Gallery).