No, I don't think so. If I had to say: Me vas aapuñalar .......... with two /a's/ together like that, I would automatically drop one /a/ and just say /vas a puñalar / Correct or not, that's what I would say.
We only use that verb when a steel weapon like a knife, bayonet or dagger is used to inflict a wound on someone. Inside prisons, lovely inmates produce prison-made knives (to kill or wound other inmates) with whatever they have at hand but I don’t think they would use needles even if they were at hand. Surely they would not want to be the laughing stock of all the other good and decent fellows.