It is something thrown in, gratis, for good measure.

He threw the bar over them for good measure.

That's all that could be construed as mad, unless they threw in the actual murder for good measure.

When its spine snapped, I threw it against the escalator steps for good measure.

Throw in, for good measure, fear of being sued over almost anything.

He threw in some obscene imagery for good measure.

It felt so good, I threw in another one for good measure.

I've reviewed some of the best below and thrown in a few free ones for good measure.

The judge threw in hard labor and twenty strokes of the cane for good measure.

She tells him to stay out of her life, throwing a martini at him for good measure.