Well, lets answer some of these pressing questions, shall we?
The first murder with a printed gun will occur some 100's of 1000's of years after the FIRST murder, and the untold millions since that had nothing to do with guns, or printed guns to be precise.
Ditto with the first accidental shooting.
Child to be killed.. hmm. I'll get back to you on that one, don't have a way to separate out the reports of children killed due to EVERY OTHER dangerous situation on the planet.
First suicide.. lets see.. around about the time someone smart enough to figure out how to print his own gun decides to take his own life and can't figure out how to obtain one of the countless other guns, knives, scarves, ropes, pills, cars ad infinitum, ad nauseum. Oh, and more power to them btw, there is truly only one thing in life that you truly own, and that IS your life. Don't tell me you think you have the right to regulate someone else's life, really?
First robbery... read above in regards to dangerous objects people use to commit robberies. OH, and while you're at it.. could you compile a list of petty thieves that have access to expensive 3d printing machines for me, hmm? I'd like to make sure we get a little perspective on this problem before it gets a little ridiculous.
Car jacking.. see above
Plane hijack.. now that one is interesting. Since the 9/11 hijacking's were supposedly carried off in part with plastic knives. What could have possibly stopped a few dangerous men with sub-standard weapons from wreaking havoc. Let me think... can't be an informed educated and trained group of men and women on the plane at the time that wouldn't have had a reason to fear a FUCKING PLASTIC KNIFE.. you know, ppl that HAD guns, or were familiar with them perhaps? Ones that didn't melt into a puddle at the mere mention of the word GUN. Nope.. I know.. lets spend untold millions of dollars creating ways to invade people's privacy, degrade and denigrate in public and prevent honest citizens from going about their lives. Yah, that sounds much more like it.