Nope, in this scenario you gifted a gun and then they sold it to someone who murdered someone. Because that’s what’s happening (ignoring that gifting is a poor analogy). You “gift” your taxes to the government who then pools your “gift” with all other “gifts” from people and businesses and other revenue streams and then “regifts” that to individual people that work for the government that then do the thing. In fact, your personal contribution to any single person’s salary is basically less than a penny. That’s a lot of guilt for a penny.
For consistency, you should then feel guilty that criminals use the roads we’ve built. After all that was government dollars used to create jobs infrastructure that murderers use to travel to kill their victim and to escape justice. And what about guns in the first place. Government tax dollars go to sustaining those gun manufacturers in the first place, otherwise we wouldn’t have guns for our military. Those guns are then used for murder and all sorts of bad things. And heck, the internet was created through government funding and many big tech companies make a lot of money from the government and that’s got a lot of crime and victimization that happens. So you should feel guilty about that too.