CHICAGO (Reuters) - Gang members sprayed bullets into a Chicago city park last week - injuring a three-year-old boy and 12 other people - after one of them had been grazed by a bullet hours earlier, police said on Tuesday. 
 
 Combination photo of (L-R) Tabari Young, Brad Jett, Bryon Champ, and Kewane Gatewood in undated booking photos released by the Chicago Police Department. The four men have been charged with attempted murder, including one suspected of firing a military-style weapon into a crowd, in a shooting last week that wounded 13 people including a 3-year-old boy, Chicago Police Superintendent Garry McCarthy said on Tuesday. REUTERS/Chicago Police Department/Handout via Reuters 
 
 The four men, who are being held without bond on charges of attempted murder, were not aiming at anyone in particular, but believed the park was controlled by a rival gang, Chicago Police Superintendent Garry McCarthy said. 
 
 “There wasn’t an intended individual...,” McCarthy said. 
 
 One of the men, Tabari Young, 22, who has been arrested more than a dozen times, used a military-grade weapon in the shooting, police said. 
 
 The man who had been wounded earlier, Bryon Champ, 21, also fired into the crowded park. Champ, a convicted felon, should not have been armed and on the streets, McCarthy said. 
 
 “When Mr. Champ was shot, he believed the rival gang controlled the territory of Cornell Park....they went to shoot up the park,” McCarthy said. 
 
 Police said Kewane Gatewood, 20, supplied the military-grade weapon and Brad Jett, 22, served as a lookout. 
 
 Last Thursday’s shooting drew national attention just days after a gunman killed 12 people in an attack at the Navy Yard in Washington, D.C. 
 
 McCarthy and Chicago Mayor Rahm Emanuel have struggled to contain street crime from gang wars in the poor, mostly African-American and Hispanic neighborhoods of the nation’s third largest city. 
 
 Emanuel called for a three-year minimum prison sentence for illegally carrying a gun on the city’s streets. “One of the shooters should have been behind bars rather than in Cornell Park,” the mayor said in a statement. 
 
 Champ had been convicted of unlawful use of a weapon in July 2012 and sentenced to boot camp, an alternative to prison, at a Cook County facility. 
 
 “He received boot camp for that gun crime and was back on the streets to be a part of this senseless shooting. That is unacceptable,” said McCarthy. 
 
 The four men are charged on three counts of attempted murder, aggravated battery with a firearm, police said, adding additional charges were expected. 
 
 The shooting took place in the Back of the Yards neighborhood in a park where residents were enjoying a basketball game on a warm evening. 
 
 Among those wounded was three-year-old Deonta Howard, who was shot in the head. Howard has undergone surgery and is expected to recover. 
 
 Slideshow (4 Images) 
 
 Gun violence in Chicago led to more than 500 murders in 2012, according to a report by the Federal Bureau of Investigation. New York City, with three times Chicago’s population, had 419 murders in 2012, the FBI said. 
 
 The number of homicides in the city so far this year has subsided, down 21 percent, according to the police department. 
 
 Chicago this year loosened one gun rule, abolishing its registry of gun owners after its gun control law was ruled unconstitutional by the courts. Illinois this year approved the concealed carrying of guns. ||||| Two suspects in their early 20s were charged Monday night in the shooting last week at a park in Chicago's Back of the Yards neighborhood that left 13 injured, including a 3-year-old boy, Cook County prosecutors said. 
 
 The break in the case came as the youngest victim of the mass shooting was making a quick recovery, walking around his hospital room and even refusing to take off his brand-new blue Nikes when he sleeps. 
 
 About 8:20 p.m. Monday, a spokeswoman for the Cook County state's attorney's office announced the charges in a shooting that once again put Chicago in a national spotlight for runaway gun violence. 
 
 Bryon Champ, 21, and Kewane Gatewood, 20, both of Chicago, were charged with three counts each of attempted murder and aggravated battery with a firearm, said spokeswoman Sally Daly 
 
 A statement issued late Monday by Chicago police said both suspects "played significant roles" in the shooting but neither was believed to be the shooter. 
 
 "These charges are just the beginning, and this investigation remains ongoing at this time," Superintendent Garry McCarthy was quoted as saying. 
 
 A law enforcement source said Champ and Gatewood allegedly helped transport the weapon used in the shooting to the scene. 
 
 Another source said Thursday's shooting was in retaliation after one of the suspects had been grazed earlier in a gang conflict in Back of the Yards. 
 
 Police identified Champ as a convicted felon and a documented street gang member. He was convicted of unlawful use of a weapon by a felon in July 2012 and was sentenced to boot camp at the Cook County Department of Corrections. 
 
 Both suspects are scheduled to appear Tuesday in bond court at the Leighton Criminal Court Building, Daly said. 
 
 Earlier Monday, the mother of Deonta Howard told the Tribune that her 3-year-old son was expected to go home in a few days despite being shot in the cheek. His face and right eye remain swollen, but he is eager to leave Mount Sinai Children's Hospital, said Shamarah Leggett, 24. 
 
 Leggett said her son will later need reconstructive plastic surgery. He had been scheduled to start preschool Monday, she said in an interview outside the hospital. 
 
 "He just keep saying, 'Ma, they shot me, they shot me with a gun. You heard me, mama?' And I say, 'Yeah, I heard you.' But I just say, 'You OK. You a big boy. You a soldier.'" 
 
 At least one gunman armed with a "military grade" rifle opened fire by a basketball court at Cornell Square Park about 10:15 p.m. Thursday. Police said it was a miracle that none of the 13 victims were killed. 
 
 Shell casings found around the blood-soaked basketball court in the 1800 block of West 51st Street were of the kind typically ejected from AK-47 rifles. Though gun violence long has plagued the city's impoverished neighborhoods, offenders almost never use military-style weapons. 
 
 Police were believed to have been questioning at least two persons of interest in the shooting since Sunday night. 
 
 Leggett said she was with her son at the park as he played basketball Thursday night. As shots rang out, people fell to the ground, either to take cover or because they were hit, she said. 
 
 As Leggett looked up, she saw her son's face covered in blood. 
 
 "He wasn't crying," she recalled Monday. "And I said, 'Baby, be still because you got a big hole in your face.'" 
 
 Leggett said Deonta makes friends easily and likes to dance in addition to playing basketball.
– Chicago police have made a breakthrough in the mass shooting last week that left 13 people injured—and led to talk of the National Guard being brought in to assist city cops. Two men in their early 20s have been arrested and charged with attempted murder and aggravated battery with a firearm, reports the Chicago Tribune. But neither man is believed to be the shooter; police believe the pair helped transport the military-grade weapon that was fired into a crowd gathered to watch a basketball game in a park. "These charges are just the beginning," a police spokesman says. One of the suspects, 21-year-old Bryon Champ, is a known gang member who was sentenced to boot camp last year for unlawful use of a weapon by a felon, Reuters reports. The youngest victim of the shooting, 3-year-old Deonta Howard, is making a fast recovery and is expected to be out of the hospital within a few days despite having been shot in the cheek, his mother says. "He just keep saying, 'Ma, they shot me, they shot me with a gun. You heard me, mama?'" she says. "And I say, 'Yeah, I heard you.' But I just say, 'You OK. You a big boy. You a soldier.'"