(CNN) -- A 15-year-old was convicted in the 2009 beating death of a Chicago honors student that was caught on video, Cook County Circuit Court officials said Thursday.

Jurors deliberated only 30 minutes before convicting the teen of first-degree murder Wednesday in the death of Derrion Albert, CNN affiliate WGN reported. The defendant is not named because he is a juvenile.

Sentencing has been set for January 18, court officials said.

When the verdict was announced, the 15-year-old threw his hands up and fell back into his chair. His aunt ran out of the courtroom screaming, WGN reported.

Authorities said Albert, 16, was an innocent bystander who ended up in the middle of a street fight between two factions of students from Christian Fenger Academy High School.

When school let out on September 24, 2009, Albert was nearly six blocks away and on his way to a bus stop when two groups of students converged on the street, authorities said at the time. The factions began fighting after an earlier shooting that police called gang-related.

Albert was approached by two members of one faction and struck in the head with a long portion of a wooden railroad tie, then punched in the face, Tandra Simonton, spokeswoman for Cook County prosecutors, has said.

After losing consciousness briefly, Albert woke up and tried to move from the fight, but was then attacked by members of the opposing faction, Simonton said.

The 15-year-old was the first of five defendants charged in Albert's death, WGN said. The other four are charged as adults.

"The facts are the facts, and the prosecutors did a great job," Albert's grandfather, Norman Golliday, told WGN. "I expected (the verdict) to be just what it was."

The trial of the juvenile contained graphic evidence, WGN reported. Police showed the wooden board used to knock Albert to the ground and contended the teen was the one who punched him in the face. The medical examiner showed pictures of the boy's body and testified he died of brain trauma caused in part by the defendant's blow. At times, Albert's family left the courtroom in tears, according to the station.

The defense attorney claimed his client, who was 14 at the time of Albert's death, was part of the fight, but maintained he did not deliver the blow that killed Albert, WGN said.

Albert's death prompted President Barack Obama, a longtime Chicago resident, to send Education Secretary Arne Duncan and Attorney General Eric Holder to the city to meet with school officials, the students and the community on the topic of school violence.