Eight of 10 victims were African American.

Two-thirds were male.

Half were younger than 15.

Arguments sparked nearly one-third of the killings. Typically, teenagers were the victims. Child abuse caused another third of the deaths. Most of those victims were younger than 5.

Arson claimed the lives of 18 children in the last five years, four of them in a single fire in October. The youngest to die in that blaze was 15 months old.

Death by gunfire

Malik Upchurch, 15, was riding his bike in Grays Ferry on a July afternoon when he was shot in the chest.

A ninth grader at James Alcorn School, Malik fell victim to a continuing turf war between rival groups of young adults who live on neighboring streets - 28th and 31st, police say. He was killed on Wharton Street, near the corner of 28th.

Police charged a 20-year-old and 17-year-old in the shooting.

Malik, who loved to play basketball and ride his bike, lived with his grandmother on 27th Street. Relatives said he was a studious child who was often bullied because of that.

Amid the turf battles, the streets near the boy's home had grown perilous. Three days before Malik's death, three men were shot in the back while sitting in a car at 27th and Latona Streets. Police said the victims were from 31st Street.

Malik's grandmother, Susie Johnson, decried the neighborhood feuding: "It's all about rivalries and retaliation. "

And guns.

Philadelphia has a thriving market in illegal handguns, often purchased legally by people who resell them on the streets.

In some neighborhoods, gun trafficking is barely hidden, experts say.

"On Saturdays, the gun sellers . . . roam the inner-city neighborhoods, selling guns out of the trunks of their cars to anyone with the money," said Elijah Anderson, a professor of social sciences at the University of Pennsylvania and an authority on the causes of urban violence.

Anderson said the cheapest weapons were those known to have been used in a murder. On the street, they're known as "guns with a body on them. "

"We have guns everywhere now," said David Fattah, cofounder of the House of Umoja, which runs one of the city's oldest antiviolence programs. "You have people riding through neighborhoods selling guns from the back of their cars. "

Last year, 171 young people were shot at in the city. Most of them were wounded, police say.