<p>October 18, 2002 -- A lying witness misled investigators in the Beltway sniper case, casting doubt on just what is known about the shadowy shooter or shooters, cops said yesterday.</p>
<p>A witness who claimed he saw the psycho who gunned down the last victim and then watched him flee in a cream-colored van may be charged with perjury or filing a false statement, authorities said.</p>