The answer is the DNA database is only as good as the information loaded into it buy local crime labs, like the one in Santa Clara County. A new audit shows innocent people had their DNA information entered into the system, meant for criminal suspects.
Santa Clara County crime analysts work on DNA evidence with hopes of solving crimes. Once they create a DNA profile, they load it into a national database called "CODIS " -- the Combined DNA Index System.
"The purpose of loading DNA profiles is to try to identify perpetrators of crime," said Crime lab director Ian Fitch.
But not all profiles developed by a lab are supposed to be uploaded.
"It has to be relevant to the crime or at least you have to feel that it's relevant to the crime and also that it is from the putative perpetrator," said Fitch.
Here's the problem, a U.S. Department of Justice audit found the Santa Clara County crime lab has shared DNA profiles it should not have shared. The DOJ looked at 100 random DNA profiles the lab has uploaded, and as a result of the audit, 44 profiles had to be removed from the national database -- what the final report calls "a large number of inappropriate profiles. ...And we believe the laboratory may have additional ineligible profiles."
"Before 2006 we concede that we entered a lot of profiles that in retrospect we should not have entered," said Fitch.
Fitch told us, before 2006, the FBI didn't give DNA labs proper guidance on what should and should not be uploaded into the database. But a third of the lab's mistakes occurred after 2006.
"The problem is the guidelines that the FBI gave us, even in 2006, they're not completely foolproof and they are open to some interpretation," said Fitch.
Take, for example, a DNA profile lifted from a cigarette butt, found in a park across the street from a homicide. Investigators thought the suspect could have smoked there.
Fitch: Can we prove that happened? No, of course not, but can we argue the cigarette was from the putative perpetrator? Yes, I think we can.
Noyes: But in a park though, where anyone could have walked and smoked a cigarette hours before?
Fitch: That's absolutely true, but again, you know, this is a murder investigation. We are trying to develop investigative leads.
The lab had to take down the profile, because there was no evidence the suspect smoked a cigarette in the park.
Auditors also found a case where a man used a wig while committing a robbery. The crime lab found a woman's DNA on the wig, yet uploaded her profile to the database even though they were looking for a male robber. It turns out, the wig had been shown to a jury in the case and the DNA profile could belong to one them.
"With that type of error you run the database, you get a hit. You say, 'Oh, this woman was connected to the crime in some way' and maybe the police show up at her door and asking her about it and all she did was show up for jury duty," said Michael Risher, with the American Civil Liberties Union. He says the audit shows cracks in the DNA database that can lead to bigger problems. "The types of mistakes that this audit uncovered are the types of mistakes that may mean that someone who is perfectly innocent could be connected to a crime, could face investigation, arrest, incarceration, even conviction, of a crime that they had nothing to do with."
Fitch says that's not going to happen. Police would investigate to determine if the DNA is really linked to a crime. But for Risher, even the police associating you with a crime is too much.
"It is a valid concern. However, I do believe it has to be weighed against the desire in society to develop investigative leads that could potentially result to the prosecution of very serious crimes," said Fitch.
Fitch and the FBI say they are working together to make sure DNA profiles from real suspects are loaded into that national database.