Updated 04/29/14 – 8:16 p.m.

CHICAGO (CBS) — A 14-year-old girl has been charged as a juvenile in the shooting death of a Tilden High School freshman who was killed Monday afternoon on her way home from school.

According to the Cook County State’s Attorney’s office, the suspect — whose name was not released because of her age — was due in Juvenile Court on Tuesday, to face one count of first-degree murder.

Endia Martin, a freshman at Tilden Career Community Academy High School, was standing with a group of teenagers in the 900 block of West Garfield Avenue – around the corner from her house – when she and another teenage girl were shot around 4:30 p.m. McCarthy said the shooting stemmed from a fight over a boy.

Prosecutors have charged a second person in connection with the murder of a 14-year-old Back of the Yards girl.

The latest to be charged is a 17-year-old boy, whom police say assisted in hiding the gun, which had been reported stolen on April 13.

The teen, whom police refused to identify because of his age, is charged with two felonies, aggravated unlawful use of a weapon and reckless damage to property, as well as two misdemeanors, unlawful use of a weapon and unlawful possession of a firearm.

“I’m very frustrated. I’m sickened. Three 14-year-old lives were changed forever yesterday by the introduction of a gun into a fistfight, and the circumstances of that gun getting into that 14-year-old’s hands are being investigated right now,” Police Supt. Garry McCarthy said.

The superintendent said, had someone not provided the suspect with a gun, the argument would have been no more than a fistfight.

“They were fighting over a boy. How long have girls argued over boys and boys argued over girls? But you introduce a firearm into it, we’ve now got a murder,” McCarthy said.

Kent Kennedy, Martin’s stepfather, said Endia was coming home from school when a student from a different school approached her.

“They had words, and she gunned our daughter down, in the back — for what?” Kennedy said. “For what reason?”

Police said the dispute started with an exchange of insults on Facebook. Both had been fighting over a boy.

“This is not the first debate about boys, but how’d did it become a homicide?”

After she was shot, Martin was taken to Comer Children’s Hospital, where she was pronounced dead. Another girl was shot in the arm, and taken to St. Bernard Hospital and Healthcare Center. Her injuries were not considered life-threatening.

McCarthy said the gun used in the shooting was a .38-caliber revolver reported stolen by its legal owner two weeks before the shooting. The gun had been stored in the owner’s car, something McCarthy said police officers are not allowed to do with their guns, but that the state’s concealed carry law allows civilians to do if they have a concealed carry permit.

Martin’s classmates at Tilden said it would be difficult to be in school without her.

“She was small, but very energetic. It’s just crazy how she had to leave like that,” senior Brittani Williams said. “I’m tired of losing my friends.”

Grief counselors were on hand at Tilden on Tuesday to speak to students about the shooting.

Rev. Renaldo Kyles, director of faith-based initiatives for the Chicago Public Schools, said it’s important for children to learn how to talk out their differences, and not settle arguments with violence.

“It’s senseless. Children have to realize that they have talk their situations out, and not bully … and just have peace circles, do more positive things and try to control the senseless violence,” he said. “Because, unfortunately, a life is taken by some things that have happened on social media.”