"Ever since that day ... if I see something as horrible and unfair as that happening, I will be the first person to be against it," Dibo said.
Moving to Gaithersburg, he said, "was a chance to reinvent myself."
South High math teacher Daniel Tusing said some students might cheer for a fight in the hallway, but Dibo broke one up.
That incident stemmed from Dibo's role as a Link Crew leader. Guidance counselor Eric Evitts said handpicked seniors help incoming freshmen adjust to their new school.
Dibo said a girl he met through Link Crew was about to get in a fight, so he grabbed her arm and pulled her away. He said he talked to her about maturity.
For the most part, Dibo said, he tries to be casual and nonjudgmental to develop a good rapport.
He's also available to peers in the guidance office, but gets few requests and spends more time assisting the staff, he said.
Dibo belongs to the school's Diversity Achievement Council and plays soccer.
Over the summer, he volunteered at Washington County Hospital.
Mark Higinbotham, his honors algebra teacher freshman year, said Dibo is one of the nicest, most pleasant students he's known.
"He's wise beyond his years," Higinbotham said.
Tusing, who met Dibo through another teacher, said almost the same thing.
"Every time I will see him in the hallway, he will shake my hand and ask me how I'm doing," Tusing said.
Evitts called Dibo soft-spoken, friendly and well-mannered.
Dibo was one of three Washington County students given Youth Meritorious Awards by the county commissioners a few weeks ago. Evitts, who nominated him, noted that Dibo's cumulative grade-point average was 3.77, including Advanced Placement classes.
Dibo is taking a history class and a chemistry class at Hagerstown Community College this semester. He has applied to West Virginia University, Virginia Tech, Penn State and the University of Maryland at College Park, his top choice, to study pre-med.
He said he'd like to be a pediatrician.
"I love kids and I really would like to work with them," he said. "I love helping people."