Here's a handy link with the various stink bugs and their developmental instars.
https://duckduckgo.com/?q=Stink+Bug+...ages&ia=images
It's amazing how bugs change shape and coloring as they go through their growth stages. Their eggs change colors too as they develop.
Stink bugs are in the order of Hemiptera and have that characteristec shield shaped scutella behind their heads. Beetles are in the Coleoptera order and don't have the scutella as part of their thorax.