Dinner in the sergeants' mess

In the sergeants' mess everything gets talked about over dinner. That day one thing was missing: nobody mentioned the depot. Four people and one grenade: one person per row, one per column. Whoever is left alone with it in the same room is the one you're looking for.

Suspects

• Anselmo, the longest-serving sergeant: He has his own seat in the mess and an opinion on everything.
• Bernardete, the cook: She serves dinner at seven sharp. Anyone arriving at one minute past gets cold soup.
• Cristiano, the duty corporal: He runs errands for everyone. That day he ran one errand too many.
• Dalila, the office sergeant: She draws up the duty rota. On that night's rota there's a name crossed out.