Future Imperfect.

On that particular day, one which had unfortunately been not that uncommon, his mum had prevented him from looking into the kitchen. The sight of his sister's blood spattered up the walls, courtesy of their dad, was more than she could stand. Never mind allowing him to see it too.

But he'd peeked around her before she could shut the door properly.

On a different day, sometime in the future, a sympathetic judge might ensure that same lad gets the help he needs. The facts of the case not justifying what he'd done but going some way to explaining it.