Police Changing Tune in Sniper Investigation

Oct. 17 -- In today's police press conference on the beltway sniper, there were a number of inconsistencies in what investigators are saying today versus what they have been saying in past days. John Miller, who has been covering the story for ABCNEWS, analyzes where the investigation may be going and why police and others may be changing their tune.

On Tuesday and Wednesday, police were very clear in saying good evidence from witnesses indicated they were looking for a cream-colored van with a taillight not working leaving the scene of the shooting Monday night. They said this info came from a witness at the scene. Composite images of two vans were released. Today they said the evidence about the taillight was no longer credible.

ABCNEWS.com: How could they have been so wrong and allowed bad information out there for so long?

John Miller: What they do is separate the witnesses, take initial first accounts and the compare the accounts. They then drill down into their story by questioning them again about their accounts, maybe three or four more times and ask them about how they met another witness. For example, when Linda Franklin was fatally shot at Home Depot in Falls Church, Va., on Monday, shots were fired and bystanders immediately rushed back into the stores. Eyewitnesses found each other and did what was natural — they compared what they saw and essentially contaminated the eyewitness accounts. Police then have to peel back those layers. They must ask if the witness remembered that piece of information of if they heard it from talking to someone else. It's urgent to get information our early when you have anything. … is not the kind of case you can sit on information — if you think at first it's going to be reliable and accurate.

At a press conference on Wednesday, Montgomery County Police Capt. Nancy Demme said one witness told police the shooter used an AK-74 rifle. Police said that weapon could fire the .223-caliber round that has been the sniper's bullet of choice. "The witness firmly believes this is the weapon," Demme said. Yet today, we hear investigators do not want people to focus on this weapon.