Bruce Bingham, a witness, says, "We noticed there was a white van sitting there."
And how is it possible so many say they heard something?
Another eyewitness claims, "I heard the shot! One single shot!"
And how is it possible that all of it adds up to so little -- not even a composite of the killer, just his suspected 'get away' vehicle.
CBS News Correspondent Byron Pitts asks, why are so called "eyewitnesses" so unreliable?
Professor Elizabeth Loftus of the University of California at Irvine explains, "The mind doesn't work like a video tape recorder."
Loftus has studied the mind of "the eyewitness" for 25 years. The more violent the crime she says, the less reliable the eyewitness.
"What the violence does is, it disrupts the processing that's necessary for full consolidation of this information into our long-term memory," says Loftus.
In a 1996 report by the U.S. Justice Department, 28 convicted rapists were released after a post-conviction DNA test proved their innocence. In 24 of the cases, eyewitnesses identified the wrong man.
Still, the word of an eyewitness remains a valuable tool in law enforcement. In the end it may play a vital role in the serial sniper case. For years the banking industry, even the CIA, have spent millions trying to build a better 'eyewitness', better observers.
In a bank robbery training tape, the bank robber also commits murder. It's a stressful situation in which tellers are trained to pay attention and remember details.
For all the weaponry and witnesses in the sniper case, it is the lack of details that have hampered this investigation. Even the intense media coverage may have helped to distort the details with images of different white vans and trucks.
Says Loftus, "New information has the potential to contaminate, distort or transform a prior recollection. And that's one of the major reasons why people make mistakes."
Still, there is little doubt. A fearful public and frustrated police agencies want the serial sniper stopped -- dead or alive. Whether it's eyewitnesses, other evidence, or an error by a killer -- who thus has been as crafty as he is cold blooded -- something will have to bring the sniper in.