The pool nobody saw

Nothing can be built in a protected area. Even so, a swimming pool appeared, with little steps, lights and an awning for when the inspectors come by. Some clues in this case come as riddles. Four people and one piece of evidence: 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

• Ascensão, the council inspector: She went to see the pool three times. Each time it was covered with an awning and she believed it was a flowerbed.
• Bartolomeu, the neighbour: He lives next door and sees nothing. He has a pool too.
• Celeste, the landscape architect: She drew the plans. On the plans, the pool is called a 'decorative water feature'.
• Dionísio, the lifeguard: He was hired for a pool that officially doesn't exist. He's paid full time.