After pulling some of the cited works in the article
@Kleanbore linked, I recognized some of the works, but hadn't seen that particular article nor the simulation results. None of the results are surprising - it's purely intuitive once you consider the logic - but I'm glad to copy and save that particular work for my own records and reference.
I REALLY want to see this simulation recreated in about 10-15yrs. We've seen a massive boom in AR-15 prevalence in the last decade, and have even seen positive-leaning news stories when AR's have been used in defense - so I'm wondering as the older generation starts washing out of the juror pool, will these results change?
I will say, in reading it - the "appearance" of the firearm, within the same model, is only mentioned in specifically in one of the cases cited in the article (Florida v. Roten), and at least in this particular case, it was NOT a defensive shooting, but rather a criminal attack. Splitting hairs, sure - but it apparently WAS used as damning evidence of premeditation or intent in that case. It's logical a tactical looking rifle would be seen as more threatening and yield a more negative juror response than one less so - but that's a comparison of an AR-15 to a Mini-14, not a comparison of an AR-15 with a Punisher Skull or Zombie Shark engraved in the receiver compared to one with a Bushmaster Rattle Snake or DPMS Panther.
The entire premise of that article and that of those arguing against APPEARANCE modifications to firearms and resulting juror opinion is completely logical -
if you intentionally appear threatening, you should expect to be perceived as having done so. Look at the news coverage after any shooting in recent eras - they go straight to social media, then cite the devolution of the shooter or the violent nature or unstable mental condition, so on, so forth... Many of us here, placed under media investigation, could be cited for having made thousands and thousands of posts about firearms online for many years... Spin that negatively in a liberal media outlet and it sounds terrible, and could sway juror opinion.
I'll say, alternatively - I don't know if I really expect a pink and purple, flowered paint job on an AK-74 to help uplift juror opinion as much as an aggressive sentiment on your rail cover would negatively affect juror opinion. I had a conversation once with my business attorney about an engraving of archangel Michael on my Glock - his guidance was while it might suit in the Midwest, I might be viewed in more liberal courts as a religious fanatic, appearing to believe I was doing God's will... It's all about perception.
I assume, however, since this thread originated from another thread on TRIGGER modifications, the intentional modification of outward appearance and the result of such on juror opinion is only the tip of the iceberg, and probably the easiest answer to the "do modifications increase risk of conviction?" question. It's simple - purposefully make it look threatening, it will be perceived as such. But what about reloaded ammunition? What about deactivating a magazine disconnect? What about having trigger work done? Installing an aftermarket trigger? Are there any cases where a functional modification, not aesthetic modification, has lead to a bad shoot conviction or civil liability IN A DEFENSIVE SHOOTING which would (most likely - as we can only speculate, right?) should have been considered a good shoot without the modification?