okay I retract my original comment about that being a possible makeshift weapon. If I had to hazard a guess that looks like a USP with a very fancy suppressor. Further reinforcing my other assertion that this was a professional hit job.
That CEO guy must have pissed off some VERY nasty people.
This image looks like it was touched up by AI. I would hold judgements like this until more information is available. But I can assure you that you are correct in your assumption: all CEOs have pissed off people, nasty or otherwise.