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A 17-year-old Morgan Park High School student limped to the front of a Cook County courtroom Friday to testify about how a seemingly minor argument can quickly turn violent on the city’s streets.

Quietly testifying at a preliminary hearing at the Leighton Criminal Court Building, Tristian Robertson said he’d seen the 15-year-old classmate in school but had never argued with him — until Oct. 30.

Standing by the judge’s bench dressed in red sneakers, black sweats and a puffy coat, Robertson said he was talking with friends at a gas station near the Far South Side school shortly after classes had ended. The classmate, Latrell “Rondo” Franklin, “hopped in” the conversation and began to “talk tough,” he said.

The two teens called each other “bitch” but then left in opposite directions, said Robertson, who stopped in an alley a few blocks away near Vincennes and Montvale avenues to talk with friends.

About 10 minutes later, Franklin jogged up to the group with a gun in his hand, said Robertson, who testified that one of his friends mistook the weapon for a BB gun.

Before Robertson could move, he said, Franklin fired off five rounds, two of which struck Robertson in the leg and stomach. Robertson fell to the ground, and as he lay on his stomach, he said, Franklin stepped up close.

“He walked up laughing and shot me in the head,” Robertson testified in a flat voice.

Judge Peggy Chiampas found prosecutors had established probable cause to proceed to trial on charges of attempted first-degree murder and aggravated battery. Bail had been set at $800,000 for Franklin, who appeared in court with his wrists shackled.

Robertson, who was shot in the back of the head, said he blacked out after Franklin left. He testified that he still suffers from vision problems, including double vision in at least one eye. Prosecutors said earlier this month that bullets are still lodged in the teen’s head and leg.

Franklin was arrested earlier this month after officers saw him involved in a hand-to-hand drug deal in the 6500 block of South Claremont Avenue and discovered he was wanted in the October shooting, according to an arrest report.

Franklin’s mother, who stood in the back of the courtroom watching the hearing, said later she has tried for years to obtain help for her son, saying he has long struggled with mental illness. She said her son lost his father and several friends to gang violence.

A court filing by Franklin’s assistant public defender indicated he has mood and intermittent explosive disorders.

The mother, who declined to be named unless the Tribune agreed to run a particular quote, said only those “who pose a threat to themselves or others can get help, leaving some mentally ill people lurching from crisis to crisis.

“They learn that if I calm down, then the crisis team leaves and I can go back to my old behaviors,” she said of her son. “The school system and criminal justice system is set up to fail.”

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