In December 2009, I announced my intention to sponsor Katie's Law, a bill requiring that DNA samples be taken from suspects charged with violent felonies. The legislation is named in honor of 22-year-old Katie Sepich, whose 2003 rape and murder was not solved for three years due to a lack of DNA evidence. Katie's mother, Jayann Sepich, has led the fight for Katie's Law nationally, and I was proud to stand with her when this proposal was unveiled.

District Attorney Mike Green, Mayor Bob Duffy and victims' rights groups have enthusiastically joined me in this effort, and I'm grateful for their support. However, a number of concerns have emerged to question whether Katie's Law takes an overbroad and even unconstitutional approach to the gathering of evidence.

In a recent City article by Jeremy Moule, a representative of the New York Civil Liberties Union focused on the potential for mistakes in DNA analysis that might lead to wrongful convictions. Others worry that collection of genetic material before conviction amounts to a breach of privacy and fundamental constitutional protections, particularly under the Fourth Amendment.

While I understand these concerns, I do not share them. Simply stated, DNA sampling of this nature is no more invasive than traditional fingerprinting - which takes place at the time of arrest - and in fact Katie's Law provides the very safeguards civil liberties advocates seek, as numerous rulings have affirmed. Furthermore, my proposal requires for DNA samples to be collected only after suspects have been formally charged, not at the time of arrest.

Individuals exonerated by the courts may have their samples removed from state DNA databases, for instance, and samples that remain are held under strict security in separate and equally secure state and federal locations.

Further, the DNA required by Katie's Law captures only a limited number of so-called genetic "markers," greatly narrowing the scope of genetic information provided about donors beyond their gender. There would be no method with which to link a DNA file with a specific name, for instance, or to discern a donor's medical history.

As for errors inherently possible in the system, I would point out that DNA technology has actually served to reverse judicial error and freed those who otherwise would have languished in prison.

On the other side of the argument we must consider those whose lives are forever scarred by criminal violence. One study conducted in Illinois concluded that 53 murders between 1993 and 2003 could have been prevented had DNA samples been acquired from just eight serial offenders.

And consider the parents of Katie Sepich, for whom justice was delayed three years because the man who murdered their daughter was absent from DNA files. Only after he was convicted and sampled in connection with a subsequent brutal crime was his DNA linked to Katie's case.

For all these reasons, I truly believe that the passage of Katie's Law in New York will aid prosecutors and the courts in determining guilt and innocence and bringing peace of mind to families touched by violent crime.

JOSEPH D. MORELLE

Morelle is the New York Assembly member from the 132nd District.