A school teacher identified a murder suspect in the case of a slain teenager during court proceedings Tuesday, nearly four years after Jordan Manners was gunned down at his Toronto school.

Former gym teacher Tracy Galbraith told the court she saw the suspect, known as C.D., in a school hallway just before Manners was shot back in 2007.

The teacher said that the young man, who had dropped out of school, was a wearing a hat -- in violation of the no-hat policy at the school -- so she told him to remove it. He removed it "with attitude," she testified.

Galbraith said she then saw Manners talking to two girls and asked them why they weren't in class. The girls left for class quickly and Manners got up slowly and walked away.

Moments later, when the teacher was in the school's computer lab, she learned that an "incident" had occurred.

Tuesday is the second day of the trial for the two accused, who can only be identified as J.W. and C.D. under the Youth Criminal Justice Act. They were 17 when Manners was shot to death at C.W. Jefferys Collegiate in 2007.

Court was also told that a photo of ammunition boxes and a poster of the film "Killa Season" were on a cellphone that Manners had at the time of his death.

Earlier, Manners' mother said she had to leave the courtroom before the trial of the two men accused of murdering her 15-year-old son got underway.

"Some of the things I didn't like, when I was here," Loreen Small explained to reporters outside the University Ave. courthouse Tuesday. "It was upsetting. It was bringing back memories and a freshness."

Small took a seat in the courtroom before Monday's proceedings began, but left before proceedings began and did not return.

When asked what things had bothered her, Small replied, "I don't really want to talk about it right now."

CTV Toronto's Austin Delaney says so far, the court has heard from a police "ident" officer, who set the scene using charts and maps so that other witnesses will be able to point to different landmarks at the scene.

In opening statements Monday, Crown attorney Aaron del Rizzo told the court that Manners was shot at close range with a .25-calibre bullet in one of the school's stairwells.

The bullet went through the teen's heart, eventually ending up lodged in his shoulder. Del Rizzo said there was little blood as there was no exit wound.

This is the second trial for the two accused. The first trial ended in a mistrial. Both have pleaded not guilty.

With a report from CTV Toronto's Austin Delaney