The murders happened in an alley near 87th Street and Exchange on the city's Southeast Side. The victims have been identified as Johnny Edwards, 13, Kendrick Pitts, 17, and 15-year-old Raheem Washington.
Detectives at Chicago police Area Two headquarters, along with gang intelligence officers, have been led to a person of interest in the case partially because of evidence gathered by police cameras near the crime scene. Saturday evening, investigators said the latest development may help them catch those responsible for killings.
It was Friday afternoon when the teens became the latest Chicago public school students to die at the hands of gun violence.
"I heard around, and the shots started ringing out. When he didn't answer his phone, I knew that he was probably one of the victims," said Washington's friend Dionte Martin.
Investigators say the attack happened Friday around 4 p.m. near 87th and Exchange as the boys walked with friends. That's when witnesses say a car carrying several men drove by and simply opened fire using at least one assault weapon.
Johnny Edwards' parents say they warned their son about neighborhood violence.
"We told him, when you hear gunshots, run in the opposite direction or else hit the ground," said stepfather Raymond Brown.
Edwards and Washington were both struck in the head. Along with Pitts, they are the 19th, 20th and 21st public school students killed by gunfire. Another CPS student, 16-year-old Rachel Beauchamp, died Saturday morning after she was shot in the head late Thursday while sitting in a vehicle on the city's Southwest Side.
While attending a previously scheduled anti-violence rally, Mayor Daley urged citizens to help police.
"This is not putting blame on anybody. It's about responsibility. If you don't take responsibility for your children, who is going to take responsibility?" the mayor said.
Police have re-canvassed the crime scene although investigators say surveillance video from police cameras may lead them to several persons of interest.
"This cannot be stood for. They have an ongoing war. We're not going to tolerate this," said Chicago police Asst. Supt. James Jackson.
In the meantime, Dionte Martin continues to struggle with the loss of his friend.
"He wasn't a bad kid. None of us are bad kids. He was just at the wrong place at the wrong time," Martin said.
Chicago public school officials said they planned on having crisis counselors available Monday to help students and staff to deal with the loss.
Anyone with information in the case is asked to call police.