"What [this law] it means to me is that there are so many other mothers that will not bury their daughters." said Sepich. "That will have the joy of having them for the rest of their lives. And I know that sounds very emotional, but people say that if we could just prevent this from happening to one other person, but there's so much truth in that."
DNA samples taken during arrest
A legally complex case begins simply. Upon arrest, a criminal suspect-- along with a mugshot and fingerprints-- opens his or her mouth and a cotton swab takes a sample from the cheek. It is placed in a vial, given a number, and stored. No consent or warrant is initially required.
Twenty-six states and the federal government allow genetic swabs to be taken after a felony arrest. Each has different procedures, but in all cases, only a profile is created -- about 13 individual markers of some three-billion -- are isolated from a suspect's DNA.
That selective information does not reveal the full genetic makeup of a person, and officials stress, and nothing is shared with any other public or private party, including any medical diagnostics. The Obama administration has signaled its support.
Law enforcement says it works and point to Chester Turner, a Los Angeles man who was arrested 21 times over the years for non-violent offenses, but never had a DNA sample taken. But after a rape conviction, he was revealed to be a serial killer, linked to at least 10 unsolved murders of women, and the rapes of other victims. He was given the death penalty in 2007.
In a brief filed by 49 states supporting Maryland, officials also say the information is secure, and retested when an initial "hit" is identified. After a warrant is issued for probable cause, another fresh DNA sample is taken and it that test that is used to ultimately prosecute in court. Each initial test costs about $30.
Every Monday those markers are compared with CODIS samples newly submitted by states.
But there are also wide differences in how the DNA taken after arrest is used.
"In Maryland, when police arrest you, they can take but cannot test that swab, until there is probable cause for the arrest, meaning that the judge says this is a legitimate, legal arrest. In other states, that's not the case," said Murphy, noting California allows testing immediately after arrest.
"And another feature that's different in the Maryland law than some laws across other states, is that if the judge finds that there has been no support for the arrest, the state has to immediately destroy all samples and purge all records from its database," Murphy said.
Other states require the person who was arrested to petition the court directly, often a time-consuming and expensive process.
Privacy advocates weigh in
Privacy advocates also say blanket collection of everyone arrested for a felony -- even non-violent ones -- is not effective as a crime-fighting tool. Murphy says police typically only collect DNA from murders and sex-based crime scenes like rape, and that expanding the evidence chain would be a better use of resources, than a sweeping collection upon arrest. Some states acknowledge boxes of DNA swabs have gone untested.
"The use of DNA is expanding rapidly so many states now engage in a process called familial searching, to collect information about the possible profiles of an individual's family members," said Murphy. "It's also possible to take the DNA profile and gleam from that inference about a person's race or ethnicity. Those are types of private information that a fingerprint never could expose."
King's attorney Kannon Shanmugam told the high court, "There are over 12 million arrests in the United States every year. Virtually all of the arguments advanced by [Maryland] and the United States would justify the blanket collection and retention of DNA from ordinary citizens."
And civil liberties groups worry inadequate testing by overwhelmed lab technicians can lead to errors, like the one that sent Dwayne Jackson to prison for armed robbery. It was three years before a lab mistake was noticed, and the Nevada man was freed as an innocent man.
Deoxyribonucleic acid is a coded molecule providing a genetic map for the development of all known living organisms. By 2000 all 50 states and the federal government required DNA collection from convicted offenders, and was soon expanded by many jurisdiction to criminal arrests.
The number of offender profiles in federal Combined DNA Index System (CODIS) is now about 10 million, with more than a million profiles of people who have been arrested.
Congress in December passed the Katie Sepich Enhanced DNA Collection Act, a grant program to help states pay for the expanded system. Jayann Sepich personally lobbied lawmakers for months to ensure passage.
President Barack Obama signed the bill last month, saying it was the right thing to do.
"In my home state of New Mexico we've had 406 cases solved since we started taking arrestee DNA January 1, 2007," said Sepich. "And that's in a state with a population of only two million people."
The first swab taken of an arrested person an hour after the law took effect produced a "hit" on an unsolved double murder.
Sepich's message is simple. "This saves lives," she said, holding a picture of her daughter. As a crime victim, "We know what it's like, and we don't ever want anyone else to ever know."