Updated 09/24/13 – 10:04 p.m.

CHICAGO (CBS) — Two more people, including the alleged gunman, have been charged in a mass shooting that left 13 people wounded in the Back of the Yards neighborhood last week.

The latest charges come just hours after two other men were charged in connection with the shooting late Thursday at Cornell Square Park, at 51st and Wood streets.

“As of right now, we have four offenders charged in this shooting, including the man who fired that military-grade weapon, and a man who supplied that military-grade weapon,” Police Supt. Garry McCarthy said at a news conference Tuesday morning.

He said the man who fired an assault rifle in the attack — 22-year-old Tabari Young — has a record including more than a dozen arrests. Prosecutors said the weapon he fired was an AK-47.

Young and three other men — Brad Jett, 22; Kewane Gatewood, 20; and Bryon Champ, 21 — all have been charged with three counts each of attempted murder and aggravated battery.

The four were denied bail at a bond hearing Tuesday afternoon.

McCarthy said Gatewood supplied the assault rifle Young fired at the park. Champ also allegedly fired a gun during the attack, and Jett acted as a lookout, according to McCarthy. Prosecutors said Champ’s gun was a .22-caliber revolver.

“Today, we bring four criminals to justice for their roles in the shooting of 13 people, including a 3-year-old child,” McCarthy said.

He said the shooting was in retaliation for an unreported shooting earlier in the day on Thursday, when Champ was grazed by a bullet.

“There wasn’t an intended individual, if I have this correctly. It’s gang-related. They’re members of rival gangs, and when Mr. Champ was shot, he believed that the rival gang controlled the territory of Cornell Park, and that’s where they went to shoot up the park,” McCarthy said. “They didn’t say ‘I’m going to go get this guy,’ they said they’re going to go shoot into the park.”

The superintendent said the four suspects would face additional charges later, and it was possible there would be more arrests in the case.

Around 10:15 p.m. Thursday, 13 people – including 3-year-old Deonta Howard Jr. – were wounded when Young and Champ allegedly opened fire at a crowded basketball court at Cornell Square Park. McCarthy has said at least 16 rounds were fired from a 7.62mm assault-style rifle.

McCarthy noted Champ was convicted of unlawful use of a weapon by a felon last year, but was sentenced only to boot camp.

“Bryon Champ was convicted of unlawful use of a weapon by a felon, which is a crime that’s designed to put dangerous criminals in jail, and he received boot camp as his punishment. A little more than a year later, he’s the main player in the shooting of 13 people,” McCarthy said. “If Bryon Champ is not on the street — as he shouldn’t have been — this incident likely does not occur.”

The superintendent reiterated the shooting served as proof that tougher gun laws are needed at the state and federal level to keep illegal guns off the streets.

“Illegal guns, and weapons designed for war, do not belong on the streets of Chicago, nor any other urban center in this country,” he said.

McCarthy and Mayor Rahm Emanuel have repeatedly urged state lawmakers to pass legislation that would impose a mandatory minimum 3-year sentence on anyone convicted of possession of an illegal firearm — and require a defendant to serve at least 85 percent of that sentence.

Current law, passed in 2011, imposes a mandatory 1-year sentence for a conviction of illegal gun possession, though a defendant could get out in as little as six months. If a convicted felon is found guilty of illegal gun possession, the current mandatory minimum sentence would jump to 2 years, with the defendant getting out in as little as a year.

“Illegal guns drive violence. Illegal guns drive murder,” McCarthy said Tuesday. “And if we don’t provide real punishment for the criminals who carry them, what message is it that we’re sending?”

All of the victims of the shooting were expected to survive, including Deonta, who was shot in the ear. The bullet exited his cheek, and he will need reconstructive cosmetic surgery to his face.

Deonta has had two surgeries so far and is said to be awake, talking and recovering well.

Deonta’s mother spoke to CBS 2’s Pam Jones outside Mount Sinai Hospital.

Shamarah Legget says her son’s first words when he came out of sedation were, “Mom they shot me and he pointed to his face like they shot me right here in my face. I’m like but you ok? Yeah, I’m ok.”

Three-year-old Deonta Howard is still recovering after a shooter’s bullet tore a gaping hole in his face.

Shamarah Leggett says criminal charges against four suspects in the shooting bring a sense of relief.

“I just started crying, but tears of joy. Not tears of pain,” said Leggett.

Minutes later, she returned to her son’s intensive care bedside, praying for the four men who faced their charges Tuesday.

CBS 2’s Suzanne LeMignot reports residents around the park hope the arrests would help reduce the violence there.

“I think it’s good they made those arrests,” said Robert Jackson, who has lived in the neighborhood for 20 years.

“I think they need to get all those guys off the street that’s in these gangs. They’re not doing anything positive for the kids. You’re taking out the black community.”

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