I think so but I seem to recall some big shot libertarian arguing no. What are your thoughts?
... just as the State
has no money of its own, so it has no power of its own - Albert Jay Nock
I don't think any bigshot libertarians argued that attempted murder isn't a crime. They might have said that it is a composite of other crimes, but I don't think any have argued that it should be a noncrime in the same way that blackmail should be a noncrime.
By crime you mean punishable offense?
No act is instrinsically a crime (in the secular world). Someone could try to kill you and you could just shrug like who cares. But if you want to live, you can't just wait around until he eventually succeeds.