Easy
The only one who fits
If only one suspect can reach a row, they are in it.
Every row holds exactly one person. So look at a row, not at a person: who can still stand in it? If the answer is one suspect, that suspect is in this row, even if they have open cells elsewhere.
This is the mirror image of pinned suspects, and it finishes most Easy cases. Check the rows and columns with the fewest open cells first.
Scan the lines, then the people
Pinned suspects start from a person and ask which lines they can reach. This technique starts from a line and asks who can reach it. Switching between the two views finds placements that either view alone would miss.
Go row by row. For each row, list the suspects who still have an open cell in it. If the list has one name, that suspect is in this row, and their cells in other rows go. Then do the columns. A 5×5 board has ten lines to check, which takes about a minute.
Why it works
The grid has as many rows as there are people, and every row holds exactly one person, so no row can stay empty. If only one suspect can still reach a row, keeping them out of it would leave the row empty and break the rule.
Where it shows up
Easy cases often end this way. After a few placements, the last rows tend to have one candidate each, and the case falls in a few moves. It helps with the victim as well: if only the victim can reach a row, the victim is in it, which can narrow down the victim's room and with it the killer.
Columns work the same way
Everything above holds for columns. On boards with tall, narrow rooms, a column scan often finds more than a row scan, since a room clue confines a suspect to a few columns at once. Try both before you reach for a harder technique.
Practice case: Easy 5×5
This case needs the technique above. Try it before you read the next tip.
She was in the Café.
Pick a suspect, then tap a cell.
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