LOWELL, Ind.- When a fleck of blood, a hair root, or a body fluid sample arrives at the State Police DNA lab in Lowell, Ind., it may be the only piece of evidence collected from a crime scene. Its value, however, will be high for both victim and criminal: If its DNA matches up in the system, the crime may be solved.

Inside the lab's "layout room," analysts in latex gloves identify DNA-containing material at a large lamp-lit counter. Working with a single sample as small as three millimeters, the DNA analysts use an array of chemicals, filters, and centrifuges to isolate and extract genetic molecules.

In the "amplification room" the molecules are coaxed into replicating themselves. A computerized machine that might have been inspired by Star Trek plunges 16 needles into gene-filled vials, creating EKG-like graphs of about 13 locations on the human genome, which together constitute a standard genetic profile that is unique to nearly every person (identical twins excepted).

Once a profile has been obtained analysts may, depending on the case, upload the information to a searchable state database, where it can be compared with other crime scene data and the genetic profiles of convicted felons. If two DNA profiles in the database match, that's called a cold hit-and is often the link needed to solve a murder or rape.

The Lowell Regional Laboratory is one of Indiana's two local members of the FBI's Combined DNA Index System (CODIS), a network of databases across the United States that makes DNA profiles nationally available to law enforcement officials. Local labs provide crime scene data to a state-run index, which in turn makes most profiles available to the FBI's national database, authorized by the DNA Identification Act of 1994.

Kristine Crouch, Indiana's state CODIS administrator, uploads DNA profiles to the federal database once a week. Except for a category for missing persons, the database has crime scene samples and convicted felons in Indiana, she said. Strict rules and detailed questions about each DNA sample govern what can be added to Indiana's database. Victims are excluded. "It's an investigation tool," Crouch said of CODIS. "It provides leads."

State databanks are governed by state law, and when it comes to whose profiles can be added to them, Indiana is among a quickly fading breed of conservative collectors. In May, Maryland joined a dozen other states that collect and store DNA from individuals arrested for-but not yet convicted of-murder or sex crimes. Fourteen more states are considering similar legislation.

Now the U.S. Department of Justice is following the expansion trend with proposed rules that could come into effect by the end of the year. Authorized by legislation originally written by Sen. Jon Kyl, R-Ariz., and passed by Congress in 2005, the new guidelines call for the collection of DNA from anyone arrested in connection to a federal crime and from detained "non-United States persons," such as illegal immigrants.

Officials believe the expansion will add 1.2 million new profiles annually, the majority of them from illegal immigrants, to the FBI's CODIS databank, already the world's largest at 6 million profiles. Barring challenges to the rules, federal arrestees who are routinely fingerprinted will find themselves opening wide for a cheek swab or submitting to a finger prick by 2009.

DNA sampling is often viewed as high-tech fingerprinting, but some privacy advocates think the storage of a potentially innocent arrestee's DNA turns the principle of "innocent until proven guilty" on its head. Sen. Patrick Leahy, D-Vt., a former prosecutor, criticized the new federal policy in an April statement: "This change adds little or no value for law enforcement, while intruding on the privacy rights of people who are, in our system, presumed innocent. It creates an incentive for pretextual arrests, and will likely have a disproportionate impact on minorities and the poor." The American Civil Liberties Union also opposed the new rules in a letter to the House Judiciary Subcommittee on Crime, Terrorism, and Homeland Security: "Housing a person's DNA in a criminal database renders that person an automatic suspect for any future crime-without warrant, probable cause, or individualized suspicion."

Such critics are overstating the case, according to Andrew Grossman, a policy analyst with The Heritage Foundation. "Certainly people have a privacy interest in biological materials," Grossman told WORLD. "But the question is, what is their reasonable expectation of privacy with respect to this particular use? It's just like adding someone's fingerprints to a database." If not charged with an offense, FBI rules allow arrestees to petition for expungement from CODIS. But "it's not something your average American is going to care about one way or another."

Looking at criminal cases, DNA profiling makes good sense. The Minneapolis murder of 33-year-old Laura Lynn DeMeules in 2005 led investigators to dead ends until late last year, when a DNA profile from a man convicted of a drunken driving felony was uploaded to the state's database. The profile matched DNA collected from skin scrapings found underneath DeMeules' fingernails. Under questioning, Antonio Medina admitted to the killing, and in April he was charged with second-degree murder.

Like most states, Minnesota records DNA samples from all convicted felons. As of February 2008, CODIS matches had assisted nearly 1,000 investigations in Minnesota and more than 46,000 investigations throughout the nation. Because cold hits on violent crimes are often made when a suspect is convicted of a minor offense, advocates of DNA profiling emphasize that the system prevents serial killings and rapes by identifying perpetrators and keeping them off the streets.

In 2004 an independent study commissioned by the Department of Justice identified over 100 specific murders and rapes that could have been prevented if the states where they occurred had collected DNA samples for felonies. Meanwhile, Minnesota is being challenged for that very practice in a state Supreme Court case over whether the state's database provides "unreasonable searches" under the Fourth Amendment.

DNA isn't just used to establish guilt: Since 1992 an organization called the Innocence Project has used DNA testing to exonerate more than 200 individuals wrongly convicted of crimes.

Jennifer Lahl, founder and national director of The Center for Bioethics and Culture Network, a conservative bioethics think tank, said there are pros and cons to database expansion. "On its face value I don't have a problem with this kind of technology, because it's just an extension of catching bad people, and making sure we convict the right people. What do we have to do as a society to make sure innocent people aren't wrongly accused, that innocent people aren't tracked and monitored, that innocent people are allowed to be free, private citizens?"

U.S. law-including the Genetic Information Nondiscrimination Act, signed May 21 by President Bush-prohibits DNA from being used to investigate personal traits or disorders, either by CODIS labs or insurance companies. In addition, the genetic information contained in CODIS profiles is extremely limited, and includes only 13 locations on the genome out of thousands. Labs like the one in Lowell are normally only equipped to profile about 16 loci and can discover little more than whether the DNA source is male or female. But since labs always save half of the original sample for legal reasons, they do, strictly speaking, store entire genomes.

Lahl said she's mainly concerned about the lack of public dialogue. "This technology is here, it's already been developed, it's already being used, and most people don't know. And shouldn't most people be aware, brought up to speed, and have a say? That's part of the democratic process."

As DNA databases expand, they're facing practical and legal challenges. Currently, the FBI and many state labs have thousands of backlogged samples yet to be analyzed (Crouch says Indiana has no backlog). The president's DNA Initiative provides up to $56 million in grants to help clear lab bottlenecks, but the problem may only be compounded as sample collection increases. On the legal front, expansion challenges how cold hits-random scans of a database for a match-are used in courts.

A recent investigation by the Los Angeles Times concluded that a cold hit could, on rare occasions, implicate an innocent person. The FBI uses a calculation called the "Random Match Probability" to determine the unlikelihood that the same CODIS profile would match two unrelated people, and prosecutors routinely present these statistics to jurors as evidence of the accuracy of DNA profiling.

Some experts think those statistics may be inflated, especially when the DNA sample is degraded and has fewer than 13 markers available for identification. As the pool of databank profiles grows, the chance of a mismatch increases. In a 2001 case in Great Britain, a man was arrested for robbery after his DNA profile was found to match six genetic markers from the crime scene. After investigating the man's alibi and agreeing to a more detailed genetic analysis, officials decided he was innocent.

The California Supreme Court will soon rule on a cold hit case involving a 1976 murder and will determine the validity of using DNA evidence decades after a crime occurred. The decision could impact similar cases across California, a state with more profiles than any other.