Is it possible that JFK assassins fired the 1st shot as a signal and simultaneously fired 2 shots to make it sound like one hitting JFK 2 bullets in his head 1 from back and 1 from front?

1st: There is very little that is not "possible" but there really isn't any reason for a potential conspirator to plan it that way - providing there ever was a conspiracy. 2nd: If there was more than one shooter in Dealey Plaza, we know that not only was Lee Harvey Oswald one of them, but also that Oswald was the only one that hit anything. 3rd: If there was a second shooter firing, he hit absolutely nothing. He not only missed JFK, he missed everyone else in the limousine, he missed the limousine itself, he missed all the crowd in the background, he missed all the buildings, trees shrubbery and absolutely positively everything else in the backshoot. 4th: In short, the second shooter left absolutely no evidence whatsoever that he ever existed. That's why there is no evidence of a conspiracy. 5th: Reiterating the 1st point, yes, it's "POSSIBLE" that a 1st shot fired was a signal to for follow on shot(s). It's just not in the least bit likely, nor is there any evidence for it, nor is it even a good idea to plan the conspiracy that way. I hope that helped.