Chicago's top police official says an assault style rifle with high capacity magazine was used in Thursday's park shooting that injured 13 people, including a 3-year-old child.
"Its a miracle in this instance there were no fatalities," Police Superintendent Garry McCarthy said at a press conference on Friday.
McCarthy added that based on witness interviews, the attack appears to be gang-related, as several of the victims are gang members. It is still unclear whether more than one person opened fire, he said.
Witnesses said several gunmen fired at least 20 shots at a group gathered at Cornell Square Park, on the 1800 block of W. 51st Street, shortly before 10:15 p.m. The spray of bullets sent a mass of people to the ground on the basketball courts.
"Man, I think it was like an AK. It was a lot of shots. Like, 'Boom, boom, boom, boom, boom, boom, boom,'" said one witness who identified himself as Josh.
The victims included 10 males and three females, including 3-year-old Deonta Howard -- known as "Tay-man" -- who was shot in the jaw at listed in critical condition as of 3 a.m. The boy was with his mother. She was not injured, a police spokesman said.
Chicago's gun violence was thrust into the national spotlight earlier this year following the death of Hadiyah Pendleton, a 15-year-old girl who was shot as she sought cover from a rain storm just days after President Barack Obama's second inauguration. Police have since employed a number of tactics aimed at reducing crime, including infiltrating problem areas with foot patrols and paying as many as 400 officers overtime each night to increase patrols in certain neighborhoods.
McCarthy said his department's data shows homicides are down 23 percent in 2013 compared to last year and insists the strategies are working. FBI data released this week, however, still showed Chicago led the nation in the number of homicides last year.
"Illegal guns drive violence, and military-type weapons, like the one we believe to have been used in this shooting belong on battlefields, not on the street or on the corner or in a park in the back of the yards." McCarthy said on Friday.
The crime statistics hit close to home for the family of the youngest victim of the city's latest high-profile shooting. Howard's grandmother, Semehca Nunn, said she lost her son to gun violence earlier this month.
"It needs to stop," Nunn said as she broke into tears. 'Y'all are out here killing these innocent people: kids, parents, grandparents, mothers, fathers. It's got to stop. Y'all need to stop."
Thursday's shooting happened nearly three weeks after a deadly Labor Day weekend left dozens injured and at least seven people were killed, including Howard's uncle, the family said.
"I just buried my son and now I'm going through something else," Nunn said.
The other victims ranged in age from 15 to 41 years of age.
Police offered no description of the shooters other than that they were black males. No one was in custody as of 10 p.m. Friday, officials said.
Mayor Rahm Emanuel, who flew to Washington, D.C. on Thursday, canceled planned meetings with cabinet officials and headed back to the city.
"Senseless and brazen acts of violence have no place in Chicago and betray all that we stand for," the mayor said in a statement. "The perpetrators of this crime will be brought to justice and prosecuted to the full extent of the law."
The mayor met with Howard and his family before attending a neighborhood prayer vigil.