Use Dudley

You like to keep your hands clean. You control over Dudley easily as he's an idiot and control all evidence pertaining to the case. You now use a spell which makes it see through Dudley's POV thus operating from afar.

Dudley responds to your basic and some complex commands with ease.

You tiptoe towards the attic and start your action.

Petunia is weeping around her Husbands photo. She is wearing a deep neck, sleeveless black dress which covers up to the knee. You command Dudley to act normal as other Muggles are around her. The police were Confunded well by you to cover your tracks.

When all the other muggles leave. Dudley then walks up to his mom who is still sad. You then regain control over him...