WASHINGTON -- Laura Neuman was raped when she was 18 years old. It took nearly 20 years to identify her attacker, even though he'd been arrested six times before her attack and at least six times afterward. 

Alphonso Hill pleaded guilty in September 2002 to raping Neuman and was sent to prison for 15 years. A DNA sample, taken in prison, led to charges in six other rape cases.

Police say he's also a suspect in at least 20 rapes in the Baltimore, Maryland, area. Hill denies raping any women besides Neuman, and his lawyer wouldn't comment.

If Hill is eventually proven guilty, Neuman believes that he could have been stopped.

"He could have been caught sooner if DNA had been taken and he had been matched to the cases that were unsolved," she said.

"For me, it would have made a profound difference in having the case solved sooner and for many of these women, their cases would have been solved sooner."

So she went public with her story, lobbying fiercely in her home state, Maryland, for a law that would require police to take DNA samples from everyone arrested for a violent crime. She testified before the state Legislature. Watch Neuman talk about her quest »

On Tuesday, Maryland starts expanding its DNA database, collecting samples from people arrested for murder, rape, and assault instead of just collecting DNA from convicted criminals.

Maryland is joining a dozen other states in expanding its database, and walking straight into controversy. To

  supporters, building DNA databases with samples from the unconvicted is no different from collecting fingerprints. Critics say it's a complete violation of civil rights.

"This is information that leads to all sorts of basic data about who we are, our entire physical makeup," said Caroline Fredrickson, director of the Washington office of the American Civil Liberties Union. "That is really different than a few fingerprints."

  Fredrickson added that there are already too many examples of racial profiling and innocent people being rounded up in police dragnets. "Our privacy is a critical factor and we can't assume that everybody is guilty until they are proven themselves innocent," she said.

Like it or not, it's a trend that is gaining popularity.

At least 21 other states are considering proposals similar to Maryland's.

Changes are coming at the federal level as well. The government soon will begin collecting DNA samples from anyone arrested or detained by the feds, including illegal immigrants.

"I think there is a valid public policy for doing that because there are many people who have committed crimes but who have never been convicted but have been arrested and without their DNA in the system we are not solving those crimes," said Associate Attorney General Kevin O'Connor.

Most states with the new DNA arrestee laws require the police to automatically destroy the samples if suspects are found not guilty or the charges are dropped. But federal authorities require a formal request before they'll destroy a specific DNA sample.

Critics worry the data could be misused, a charge O'Connor disputes. "Congress has passed a provision that says anybody who abuses this information, or uses it for non-law enforcement purposes such as to look at someone's family history of diabetes or whatever the disease might be ... will be prosecuted," he said.

Justice Department officials estimate when the expansion is fully implemented -- as soon as December -- information from about 1.2 million people a year could be added to the national DNA database. It's another cause of consternation for critics--who say backlogs remain a major problem.

The FBI estimates that about a quarter of a million DNA samples have yet to be processed in its lab and says it did not receive any new funds to deal with the backlog, which is sure to grow even larger. Many states are facing similar issues. CNN Reporting