Mario Sanders, 20, was accused of pushing an on-duty police officer to the ground and punching another in the face around 4:30 p.m. in the 4800 block of South Ada Street, police said.
A 19-year-old was killed and four other teens were wounded in the shooting, which stemmed from a "historic gang conflict," according to Chicago Police Commander Don Jerome.
A scuffle broke out between police and some onlookers who thought police were not performing life-saving measures on the gunshot victims. A mother who witnessed the shooting and did not want to be identified, said officers were "standing around, talking and laughing."
"They weren’t trying to do compressions or CPR on the kids that were shot," she told the Sun-Times. "That’s when the people of the community started getting reckless."
But Jerome said officers were tending to the wounded. He said no officers were injured by the "hostile crowd."
Sanders was charged with two felony counts of aggravated battery of a peace officer and two misdemeanor counts of resisting arrest.
Mitchell Rosas, 42, was also charged with resisting arrest.
Police said Rosas tried to stop officers from rendering aid to victims at the scene and starting their investigation. He ignored orders to evacuate the area, according to police.
The attack was the first of two mass shootings that occurred five hours apart on the South Side. The second occurred about five miles away in Jackson Park and wounded six people. By day’s end, at least 21 people were shot across Chicago.
Sanders is due in court Wednesday.
The Sun-Times Media Wire contributed to this report.