If you're arrested for a crime in New York, you'll get fingerprinted and photographed. Soon, in some instances, you could be required to submit a DNA sample, too.

Assembly member Joe Morelle and Senator Jeffrey Klein have introduced legislation that would require those arrested and charged with certain felonies to submit DNA samples at the time of their booking. Currently, state law requires people convicted of certain felonies and misdemeanors to submit samples which will be profiled and entered into the state DNA database.

Morelle says the legislation, dubbed Katie's Law, will help law enforcement and improve public safety. By getting a DNA profile - not the DNA itself, but a way to identify people by the unique structure of their DNA - into the state system at the time of arrest, not conviction, it increases the size of the profile pool and provides access to the profiles sooner. The law would essentially function as an expansion of the DNA database.

"This is a pretty big deal and they've gotten literally thousands of hits off of this DNA database," Morelle says.

Critics, however, say that expanding DNA collection to arrestees will infringe on civil liberties and  privacy, and that the practice subverts important parts of the legal process - namely protections centered on probable cause.

Similar laws have been enacted in 21 states. They've faced Fourth Amendment challenges in at least some states - though unsuccessfully. The Fourth Amendment protects against unreasonable search and seizure.

"I think what we need to say as a society is do we really want Big Brother having information about everyone charged with a felony and, pretty soon, everybody charged with a crime," says Monroe County Public Defender Tim Donaher. "That's where this is going to go."

The Morelle-Klein bill is named after Katie Sepich, a 22-year-old from New Mexico who was attacked outside of her home in August 2003. She was raped, strangled, and then her body was set on fire and abandoned at an old dump site.

Law enforcement officials found skin and blood scrapings under Sepich's fingernails, which provided a link to her attacker. But law enforcement officials couldn't find a match in DNA databases.

The attacker had been arrested several times, but it took three-and-a-half years for him to be convicted in another state, which then compelled a DNA sample. After that, law enforcement officials "hit the match," Morelle says. Convicted felon Gabriel Adrian Avila confessed to the crime.

Proponents of the legislation say taking the samples at time of arrest could help law enforcement catch repeat offenders quicker and may even prevent crimes. It also could help quickly exonerate suspects, they say.

A DNA sample is how Keith Laster was connected to a series of child rapes from the 1990's, says District Attorney Mike Green. Law enforcement officials used evidence from the rapes to develop a DNA profile of the suspect, which was then entered into state and federal databases. The case sat open with no hits until 2004, when Laster was arrested in Alabama on rape charges. Sometime after his arrest, police took a sample of Laster's DNA and added it to their databases. Once it was entered, it came up as a match to the profiles from the Rochester rapes. Laster was ultimately convicted of multiple accounts of first-degree rape, as well as other charges.

"The larger the database we have, the more crimes we're going to solve," Green says.

Green favors expanding the database to include anyone convicted of a crime and anyone arrested for a crime - he points out that Laster was also charged with misdemeanor drug possession in 1996. If a DNA sample had been taken then, Green says, a 1997 rape could have been avoided.

DNA is not infallible, however. The technology is good and it works, but people sometimes make mistakes, says Norah Rudin, a forensic DNA consultant from California. And while the profiles entered into New York's database come from one person in a controlled environment, the same can't always be said for crime-scene samples. It's common for those samples to have DNA from more than one person, Rudin says, or to be too small in quantity for a definitive analysis. In those cases, the DNA tests must be interpreted by lab technicians, which is where the human factor - and potential for error - comes in.

"People rarely advertise the limitations," Rudin says.

Critics also say that collecting DNA at the time of arrest bypasses probable cause standards and due process.

Law enforcement agencies currently must get a court order to compel a DNA sample from a suspect. That means the request is subject to review by a judge, who can determine whether there is probable cause - that's not the same as innocence or guilt - that the suspect committed the crime for which he or she has been arrested. The judge would also determine whether there's a clear indication that the suspect's DNA will be somehow relevant to the case.

"The problem with this legislation is that there's no judicial determination," Donaher says.

Donaher and another attorney in his office, Kimberly Duguay, are drafting a memorandum in opposition to the legislation.

The way this all works is laid out in a state Court of Appeals ruling commonly known as Matter of Abe A. The decision laid the ground rules for taking blood from a suspect. At the time the blood wasn't being drawn for DNA analysis, but rather blood typing. Since then, however, the ruling has been applied to DNA sample collection as well - whether it's a blood draw or an oral swab. The protections, as the decision puts it, are meant to guard against a "fishing expedition."

That's a concern that routinely surfaces during proposed expansions of New York's DNA databank. When former Governor Eliot Spitzer proposed expanding the databank in 2007, the New York Civil Liberties Union cautioned against such a move and reminded state officials of their duty to protect the due process rights of those whose DNA profiles the state archives.

"The collection and analysis of forensic DNA evidence is highly susceptible to human error and botched DNA analysis has led to many cases of wrongful prosecution and conviction," says Jennifer Carnig, communications director for NYCLU.

People arrested and charged with crimes, however, are already treated differently than someone who's not charged with a crime, Morelle says. They can be held on bail and they're fingerprinted. And there's some degree of suspicion that the person committed the crime, Morelle says.

"There are so many safeguards in the system that the information is just not revealing in any way and the benefit you get as a society - that's to both the innocent and guilty, and victims - outweighs whatever concerns people express," he says.