CHICAGO (STMW) — Skokie police have released the person they say pulled the trigger in the fatal shooting of a Niles North High School student last month.

The 17-year-old male had been arrested Monday at his Chicago school. At the time, police had said they expected charges to be filed later Monday.

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Instead, the teen was released on Tuesday as investigators say they are continuing to build their case. The Cook County State’s Attorney’s office did not think there was enough evidence at this time to charge him, according to Skokie police officials.

Skokie police said they continue to believe this suspect is the person who pulled the trigger in the murder of Maxwell Gadau, 17, a senior at Niles North.

That shooting last month also left a 17-year-old female friend of Gadau wounded. She also is a senior at Niles North.

Four people remain in custody. Three had appeared in court on Sunday, and on Monday morning, the fourth Dzevad Avdic, 19, also appeared in court.

Avdic is the man prosecutors say planned the botched robbery that led to the fatal shooting. He was ordered held without bond.

Cook County Judge Marcia B. Orr said Avdic constitutes a “real and present threat,” to the public and to the second shooting victim, a female who remains in the hospital in critical condition.

Avdic, of the 5900 block of South Honore in Chicago, is charged with murder, attempted murder and armed robbery.

Prosecutors said in court that Avdic is alleged to have planned the crime and called another suspect, Jeremy Ly, asking for a “stain or a lick” — street talk for an easy target.

Besides Ly, who lives in Skokie, the others charged are Myles Hughes, of the 4200 block of West 81st Street, Chicago; and Nicholas Smith, of the 3800 block of West 84th Street in Chicago. All are 19.

All four have been charged in Gadau’s murder, as well as the attempted murder and armed robbery of the girl. Cook County Judge Peggy Chiampas ordered the three who appeared in court Sunday to be held without bail.

Ly is accused of suggesting the name of the 17-year-old girl to Avdic, saying she would be easy to rob if Avdic had a gun, prosecutors said Sunday.

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Ly was wrong. When he and four others finally lured the girl and Gadau into a car under the guise of a drug deal last month in the 9200 block of Kedvale in Skokie, a prosecutor said she refused to be robbed, even at gunpoint.

So a gunman fatally shot Gadau in the back and shot the girl in the face, Assistant State’s Attorney David Mullner said.

Their family members declined to comment after the judge denied bail for the men, but Smith’s attorney called him “a good kid” who is the son of a pastor and who cooperated with police. Smith told detectives he was aware of a plan to “snatch and run” before the alleged robbery began, Mullner said.

Avdic, of the 5900 block of South Honore in Chicago, was expected to appear in bond court Monday.

The prosecutor said Avdic texted the girl on Sept. 24 — after Ly gave him the girl’s name and number. Avdic allegedly set up a drug deal and, meanwhile, got in touch with Smith.

Four days later, on Sept. 28, Avdic allegedly called the girl and drove Smith, Hughes and the alleged gunman to go meet her, Mullner said. Ly did not go along.

When they arrived, Hughes and the alleged gunman got into a car with the girl and Gadau, the prosecutor said. The girl sat in the driver’s seat, and Gadau sat in the front passenger seat, Mullner said. Hughes sat in the back seat behind Gadau, and the alleged gunman sat behind the girl.

The alleged gunman pulled a handgun and demanded the drugs from the girl, Mullner said. When she refused to give them up, Mullner said the suspect opened fire, killing Gadau and wounding the girl.

The four suspects fled, Mullner said. But on their way to Avdic’s home, they allegedly shared an ounce of pot stolen from the girl’s car.

Mullner said the wounded girl remains in the hospital on a respirator. He said she will need to have her jaw wired shut and will require surgery to repair her jaw and vertebrae.

But the girl was able to identify Hughes in a photograph, the prosecutor said. And she said he was an accomplice of the person who shot her.

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