Some offenders don't realize they can have their records expunged if they apply for it.
Juvenile records, which can range from underage drinking to more serious offenses, can follow people into adulthood and mean lost job opportunities, and trouble enlisting in the military and getting into schools.
"What happens when you're a juvenile carries on into adulthood," said Keir Bradford-Grey, the Montgomery County chief public defender. "It's our obligation not just to figure out how to put a Band-Aid on their legal problems," but to keep youngsters from getting in more trouble.
Her office estimates thousands of children throughout Pennsylvania, and perhaps a couple of hundred in the county, get their records expunged yearly.
The office, through a weekly clinic with Villanova University law students, has helped 18 former clients get their juvenile records expunged since the effort began in September, she said. She decided to start it after learning about a similar program in Philadelphia.
Redemption is the core theory behind a separate juvenile law system.
"The juvenile court was premised on this idea of confidentiality and informality," said Riya Saha Shah, a staff attorney with the Juvenile Law Center in Philadelphia. "It really was supposed to be a court of rehabilitation and a court of second chances."
It still is supposed to steer children, whose brains continue developing into their 20s, toward law-abiding behavior.
"What we know and what people have known for years is that kids do stupid things," Shah said. "They don't make the same mistakes when they are 13 years old as they do when they are 23 years old as they do when they are 43 years old."
Expunging juvenile records is not a new process, but it has taken on more significance since 1994, when serious juvenile crime peaked, said Philip Harris, an associate professor of criminal justice at Temple University who studies juvenile delinquency and recidivism.
Some cases were so disturbing, he said, that the most aggressive children were seen as a new class of "super predators."
"That was a very, scary time for people," he said, "and a time when the police and courts were overwhelmed."
As a response, many states passed laws that allowed juveniles accused of serious violent crimes to be tried as adults, and to have juvenile records made available to adult criminal courts that might consider them for sentencing purposes.
Since the mid-1990s, the rate of serious juvenile crime has dropped, Harris said. But laws remain that make it hard for young people who committed less serious crimes only once to shake their records.
In Pennsylvania, young offenders may be able to have their records expunged after completing their court supervision and filing a petition with the court, said Craig B. Bluestein, chief of the public defender's child advocacy division.
An expungement order would not cover private sources of information, such as websites that collect and publish criminal histories. Online searches also might turn up records that have been expunged.
Some offenses might not be expunged even from public files.
"I think we're very cautious," Montgomery County District Attorney Risa Vetri Ferman said. "In cases involving the most serious offenses, primarily violent offenses or significant property, drug crimes, and things like that, we will not agree to expungement."
Bradford-Grey is trying to reach young offenders like Darden.
Darden has had no problems with the law since the purse-snatching.
But as she was trying to get into a program to become certified as a nurse's aide, a background check turned up her theft adjudication - in juvenile law, a criminal conviction is called a delinquency adjudication - and blocked her. She couldn't get into the program, she was told, until the record was expunged.
In February, public defender program manager Leane Renee guided Darden through the clinic to get her record expunged.
Darden now lives in Warminster, works at two jobs, and is studying to be a nurse's aide at Bucks County Community College, where, she said, she has a 3.7 grade point average.
Eventually, she would like to become a juvenile probation officer.
Darden never has spoken with the woman she victimized, but might some day so she can apologize and explain.
She would tell the woman she took the purse because her family had little money and her mother was too ill - she suffered two strokes the same year as the purse-snatching - to bring in income. Her mother has since died.
Darden would say she was embarrassed at school because of the ragged clothes she wore, and she didn't want to be embarrassed.
She would say none of that was reason enough to snatch away what wasn't hers. Darden takes responsibility for her actions.
She also knows she wouldn't do it again.
"It's not like I'm the same person," she said.