Here’s some fatalities from guns around that power or less:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC500806/
Muzzle energy isn’t the only factor in lethality.
Muzzle energy isn’t the only factor in lethality.
If the projectile was some kind of sharpened dart, 16J might be enough to be lethal in a headshot. Maybe. I'd have to do a test to see if it could punch through mass equivalent to the bones of the skull. But a disc or a ball? Unlikely. Could take out an eye, sure, but that's about it.
Absolutely unsuitable as a weapon.
Also at least two of the weapons detailed was below 12 ftlbs which means it was definitely below 16J. Further when you get on to the discussion you will note it says all the weapons were within legal limits. So your reading of the article is incorrect.
The actual legal limit for “lethality” as it pertains to defining a firearm in the UK is 1.35J.
I re-read, and you are correct!
I'd still be surprised if this was a common occurrence with projectiles of such low power, but if ballistics against key targets (heart and brain through the skull) show consistent penetration at that power level with a steel ball, I'm happy to update my assumptions as to power and lethality.
(I'd be surprised if they did, but it'd definitely change my mind should the results be consistent)