[flamberge]

Badly-fitted plate on a bullet-proof vest would be my first guess.

Could be a device for continuous injection and monitoring of medications.

Could be a device that performs as a location monitor and medical alert.

Whatever it may be, is not likely to make much difference in national affairs.

[upchuck]

Could be a device for continuous injection and monitoring of medications.

BINGO!

[Cincinnatus.45-70]

I agree that it’s possibly a badly positioned rifle plate. The picture looks like it’s outdoors, so they may just hang that over his dressier body armor when his is potentially exposed to rifle fire.