The Web site JimRomenesko.com has a report from Alan Peppard of the Dallas Morning News about a talk at Southern Methodist University by the executive editor of the New York Times, Jill Abramson:
While here, she visited the Sixth Floor Museum (in the old Texas School Book Depository) and she watched Cronkite's first bulletin. She commented on how, unlike today, the first report was quite accurate. 'In Dallas, Texas, three shots were fired…'
Yet a closer look shows the accuracy of that initial CBS report (a YouTube video of it is here) — in particular, how many shots were fired — is still open to question, and is certainly not as clear-cut or closed a factual matter as the Cronkite report, and Ms. Abramson's apparent endorsement of it, suggest. Here is how the author William Manchester put it in his authoritative 1967 book The Death of a President (p. 155):
The plaza is an acoustical freak, and this writer, like the Warren Commission, could not determine how many shots were fired by the assassin. Two found their mark. A majority of witnesses say they heard three detonations, and three spent shells were found in the sniper's perch. Yet several witnesses closest to the scene—e.g., Mrs. Kennedy, Clint Hill, Zapruder—heard only two reports. And it would have been typical of Oswald's laxity to have come to the warehouse with an expended cartridge in the breech, which would have required removal before he could commence firing.
Manchester goes on to write that, "However, three shots may well have been fired."
Here is the Warren Commission's discussion of the issue, from chapter three of the report of that official government commission set up to investigate the assassination:
The consensus among the witnesses at the scene was that three shots were fired. However, some heard only two shots, while others testified that they heard four and perhaps as many as five or six shots. The difficulty of accurate perception of the sound of gunshots required careful scrutiny of all of this testimony regarding the number of shots. The firing of a bullet causes a number of noises: the muzzle blast, caused by the smashing of the hot gases which propel the bullet into the relatively stable air at the gun's muzzle; the noise of the bullet, caused by the shock wave built up ahead of the bullet's nose as it travels through the air; and the noise caused by the impact of the bullet on its target. Each noise can be quite sharp and may be perceived as a separate shot. The tall buildings in the area might have further distorted the sound.
The physical and other evidence examined by the Commission compels the conclusion that at least two shots were fired. As discussed previously, the nearly whole bullet discovered at Parkland Hospital and the two larger fragments found in the Presidential automobile, which were identified as coming from the assassination rifle, came from at least two separate bullets and possibly from three. The most convincing evidence relating to the number of shots was provided by the presence on the sixth floor of three spent cartridges which were demonstrated to have been fired by the same rifle that fired the bullets which caused the wounds. It is possible that the assassin carried an empty shell in the rifle and fired only two shots, with the witnesses hearing multiple noises made by the same shot. Soon after the three empty cartridges were found, officials at the scene decided that three shots were fired, and that conclusion was widely circulated by the press. The eyewitness testimony may be subconsciously colored by the extensive publicity given the conclusion that three shots were fired. Nevertheless, the preponderance of the evidence, in particular the three spent cartridges, led the Commission to conclude that there were three shots fired.
In other words, the only sure thing is that at least two shots were fired. Different witnesses heard different things. And the illusion of authority or accuracy conveyed by Cronkite's report may have made it harder for investigators to gather unbiased testimony after the fact. The bottom line is that you don't have to be Oliver Stone or some JFK assassination conspiracy theorist — which I am not — to realize that, rather than being an example of accurate early reporting as Ms. Abramson hailed it, Cronkite's "three shots" bulletin is a reminder of the importance of carefully attributing sources of this sort of information — "according to police," "according to some eyewitnesses" — of describing the way that the information was developed — "the witnesses said they heard three shots," "the police said they recovered three spent cartridges" — and reminding readers or listeners of the limits of what is known.