Bell was approached by two men on the 4900 block of West Sheldon Street about 9:40 p.m. on Dec. 23, said Philadelphia Police Capt. James Clark, head of the homicide unit. The men announced a robbery, Clark said, but Bell apparently fled, and one of them fired.
Many who die from gun violence in Philadelphia were involved in drugs or other illegal activities, according to police. But some, like Bell, were not.
"I could understand it if my son had a gun, or if he was part of what goes on out there," Tina Bell said. "But my son was never like that. He was just walking down the street."
"This was a good kid, a hard worker," Clark said. "He was about to start a new job. He was innocent."
The city's homicide count was up 12 through Friday compared with the same period a year earlier. Meanwhile, police say the clearance rate for homicides has dropped.
In 2009, the department's homicide clearance rate was close to 80 percent, believed to be the highest of any major U.S. city. Just three years before, Philadelphia's clearance rate had been slightly below 60 percent, which is about the national average for cities with more than half a million people.
In 2011, the clearance rate was closer to 60 percent, Clark said.
"I can't say there's a real reason for it," Clark said. "Some of these investigations take longer than others. We're going to keep working these as hard as we can until we can bring them in."
Reducing the city's crime was a key pledge when Mayor Nutter took office in 2008. During his inauguration, he said: "We are going to change the mentality of those that think it is OK to run our streets with illegal weapons and use them at random whenever they want. . . . This is our city and we're taking it back, every day, every block, every neighborhood, everywhere in Philadelphia."
That year, Nutter pledged to cut the homicide rate by 30 percent to 50 percent within five years, and he chose Charles H. Ramsey as police commissioner. A year later, homicides were down 15 percent, the biggest drop in a decade. As of Friday, the rate from 2007 was down 17 percent.
"Unfortunately, at least here in Philadelphia, there is a mind-set, a culture that some people have no fear of . . . just running around, walking out of their house, getting in their car, walking down the street with an illegal weapon," Nutter said in a recent interview. "So that takes an even more aggressive posture to get those weapons off the street."
The unsolved case that has most haunted the city's homicide detectives in 2011 is the shooting of West Philadelphia grocery-store owner Porfirio Nunez, his wife, Carmen, and his sister Lina Sánchez.
The three were slain Sept. 6 in their store, Lorena's Grocery, at 50th and Parrish Streets in the city's Mill Creek section. Two gunmen burst in around closing time, ordered one of Nunez's daughters to the floor, and forced the other to open the cash register. When Nunez came from the back of the store, he was killed. The assailants then went to the back, where they shot Carmen Nunez and Sánchez.
"They killed them for nothing," Clark said.
Police pulled surveillance footage from the area that shows two men in hoodies approaching the store, then running away. But no clear description has emerged, and despite a $25,000 reward for information leading to the arrest and conviction of the killers, no one has come forward.
The day before that shooting, Howard Hunter, 62, and his friend Angel Heard, 54, were shot to death in Hunter's University City apartment on Wiota Street. Police believe the killings were drug-related, but the case remains unsolved.
Police also are still searching for the killer of Rolando Lugo-Almonte, 23, a store owner who was shot to death in Point Breeze on Nov. 23 after closing up for the night. As he was walking to his car at 15th and Wharton Streets about 8:30 p.m., Lugo-Almonte was approached by two men with guns who intended to rob him. He was shot several times and died about two hours later.
"People know who did this," Clark said. "We just need them to come to us with some information."
The March 30 killing of Lamont Wallace near his North Philadelphia home also has stymied investigators. Wallace, 21, worked at Citizens Bank Park and had just gotten off the subway on his way home from work when he passed two men on the 800 block of North Marvine Street.
The men asked Wallace for change, police said. Wallace refused and went into a nearby store. There, he called his cousin, Clark said, telling him he was afraid he might have some trouble with the men. Moments later, when Wallace left the store, his cousin overheard a struggle followed by gunshots.
Anyone with information about any homicides is asked to call police at 215-686-3334, or leave an anonymous tip at 215-686-8477.
Contact staff writer Allison Steele
at 215-854-2641 or firstname.lastname@example.org.
Staff writer Miriam Hill contributed to this article.