Philadelphia has seen a slow uptick in its homicide rate. Last year, 331 people were the victims of homicides, up from 324 in 2011 and 306 the year before that.

But last year's toll marks a 15% drop compared to 2007, when the city earned the nickname "Kill-adelphia" after suffering more than one murder a day.

The fact that most of those killed in Philadelphia are victims of gun violence is emblematic of a national trend: Federal data for 2011 shows that more than 67% of all homicides in the United States were carried out with a gun.

So where's the nation's outrage?

Daily, inner-city gun violence has become "white noise," said Chuck Williams, founding director of Center for the Prevention of School-Aged Violence at Drexel University.

"At this point it's like, 'Oh, another six people got shot and killed over a week in a poor black community. Business as usual,'" he said, shrugging his shoulders. "So America says, if the urban communities don't care enough about it, then why should we?"

Williams hopes that will change in the wake of the mass shooting in Newtown, Connecticut.

"If this (Newtown) is not enough for all of us to come together and say that something needs to be done, I don't know what is," he said. "Our kids are dying and they're leaving us way too soon, and we have the power to do something about that if we so choose."

'I hurt the same way'

Eddie Bocanegra, born and raised in the rough and tumble section of Little Village on the southwest side of Chicago, is no stranger to gun violence.

Bocanegra, who spent 14 years in prison for murder, is now on a mission to save lives. He is featured in the documentary "The Interrupters," which follows the lives of three community activists fighting to interrupt the fervent violence in Chicago.

The shooting in Newtown spurred the nation to respond, from prayer vigils and donations to around-the-clock news coverage of the event. Although moving, the reaction was also sobering, Bocanegra said.

"A kid growing up in the 'hood has different expectations than a kid growing up in Newtown," said Bocanegra, who works with ex-offenders at the faith-based nonprofit Community Renewal Society in Chicago. "We have worldwide attention on this tragic event in Connecticut, but it shows us how we value life, and it's a shame murder isn't treated the same across the board."

"I hurt the same way you hurt. Murder shouldn't occur, and I say that as someone who took a life," Bocanegra said. "All lives are precious, and one is not worth more than the other."

Every single day in the United States, 13 young people between the ages of 10 and 24 are the victims of homicide, according to federal data. More than 80% are killed with a firearm.

In Philadelphia, the majority of homicide victims are African-Americans between the ages of 15 and 24.

"Every time there is a loss of life, we have to remind ourselves that these are often children. And we have to ask ourselves where have we failed to protect this child?" said John Rich, director of the Center for Nonviolence and Social Justice at Drexel University.

The indifference toward urban slayings often comes down to "victim blaming," said Rich, author of "Wrong Place, Wrong Time: Trauma and Violence in the Lives of Young Black Men."

"We're using shorthand and stereotypes to draw a conclusion," Rich said. "There's something undeniably different when we have this scale of horrible in Connecticut. And there's something undeniably horrible about a killing a day."

Trauma, poverty and unsafe neighborhoods must be included in the gun control debate, said Ted Corbin, co-director at the Center for Nonviolence and Social Justice.