The Force Field is the tiny drone helicopter you can
see hanging from the SWAT Officer's belt (above).
I do a few things which constitute my day jobs. Most of them have to do with consulting with governments and various companies. At Ashima Devices, I work to create some very cool "devices", some of which you can view on the website and some of which, you can't.
FOX NEWS carried one of the devices on its military force protection top ten list. The smaller variant is shown below in its prototype development phase. The advantage of this unit is two-fold. First, it's very small and is usually carried inside a nylon pouch on a police officer's or soldier's belt (ALICE or MOLLE) and secondly, it's very inexpensive.
It's not simply a camera on a quadcopter because the image taken by the camera is 3D. You can read more about it on the Fox News link or on the Ashima Devices website.