Miller: The trouble with the descriptions is that some witnesses didn't agree. So trying to generate a sketch would be a useless document. During Son of Sam, a set of six or seven sketches came out over the course of a year. The profile went from being a guy with long brown hair combed over to a guy with curly hair with a receding hairline to something else entirely. There were half a dozen sketches and ultimately none of them looked like David Berkowitz — but they looked different from each other too. The danger of releasing sketches is that it sends a message to public that this is what they are looking for. Someone may think they know someone who they think could be a suspect, but they may look at a sketch and say 'he doesn't look anything like that' and not report them. This investigative aid can do investigative harm if the source is unreliable. When you see a sketch and see the guy ultimately caught, the sketch should optimally look like a photograph. But that won't be the case here because they don't have a sketch they're confident enough to release.
Dr. Richard Ratner, a criminal psychiatrist in Washington, D.C., said every word spoken by authorities is now "based on some estimate of what you think is going on in his head.
ABCNEWS.com: Are investigators deliberately acting confused or offering pieces of information that may draw the sniper, or snipers, out? Or, are there big problems with interagency squabbling?
Miller: Early on, investigators were speaking frankly and candidly and including their own feelings and thoughts on the case. Since the sniper has continued to kill, investigators have dialed back and switched to asking help from the public and delivering facts without characteristics. They've now take a more "just the facts, ma'am" approach.
Investigators seem concerned about leaked information, but so far, there appears to be little of that except for the information about a tarot card left at the scene of one of the shootings.
ABCNEWS.com: Is this just a smokescreen? Miller: They are concerned about leaking information, and media people trailing witnesses through the streets — to the point that they will go to the media and tell them not to look at them. They have worries. It is very difficult to conduct a serial killer investigation in a fish bowl. You don't want them to see you coming, especially on live TV. However it's almost impossible to conduct in a vacuum because so much depends on facilitating information from the public. It's a double-edge sword and delicate balance for them.