Police Body Slam 80 Year Old Woman

This is just sad. Apparently she was waving a knife in the parking lot of a Wal-Mart. But seriously, I'm not saying that's right, if it's indeed true, but couldn't they just have grabbed it our of her hand with minimal force? I'm sure she couldn't overpower them, and is backup really necessary? It's disturbing to see such a elderly woman get slammed like that on the concrete. Thanks to CiTeach for pointing this out.