(CBS) – Two men who allegedly played “significant roles” in last week’s headline-grabbing mass shooting have been charged, police announced Monday.

Neither suspect — Kewane Gatewood, 20, and Bryon Champ, 21 – is believed to have pulled the trigger Thursday night at Cornell Square Park, where 13 people were hit by gunfire from a military-style assault rifle. The injured included Deonta Howard, a 3-year-old boy who was shot in the face; all victims survived.

Gatewood and Champ were each charged with three counts of attempted murder and aggravated battery with a firearm.

“Chicago Police Detectives continue to work tirelessly to solve this case and hold the criminals who committed this senseless act of violence last Thursday night responsible for their actions,” Chicago Police Supt. McCarthy said in a news release. “These charges are just the beginning, and this investigation remains ongoing at this time.”

Gatewood allegedly secured the weapon that was used in the Back of the Yards shooting, a source tell CBS 2 Chief Correspondent Jay Levine. Champ, a convicted felon and documented gang member, allegedly then gave the military-style weapon to the shooter who sprayed gunfire at the crime scene at West 51st and Wood, the source said.

More individuals are expected to be charged. Police scheduled a news conference for Tuesday morning.

The shooting was gang-related, police have said. McCarthy said it was a “miracle” no one was killed, given the type of weapon that was used.

The bloody incident drew national attention and reinforced the perception that crime is rampant in some Chicago neighborhoods. Officials say crime is actually down, based on statistics.