"We were so happy," Harris said. "We were high-fiving and doing all of that."
Three years later, the 21-year-old's degree is hung proudly by the mantle.
But when Harris applied for a new job, his boss was told by Gwinnett County Schools that his diploma was given to him by mistake. He never passed the science portion of his final gateway test.
"Right now, it feels like it's ridiculous," Harris said. "Right now, it feels like I have to go back to school again, but this time high school."
In the days after graduation, Harris did retake the test once, and the family never heard anything else, so they assumed all was fine.
That was until a few days ago.
"This is not right," said his mother, Anita Harris. "I'm not going to allow you to do my son this way."
WSB-TV contacted the school district for its side. A spokesperson said the family should have gotten a phone call three years ago but the records weren't available immediately to determine if that happened.
"Our goal is to help this student so that he can meet all graduation requirements and have his transcript and diploma show that he is a Gwinnett graduate," spokesperson Sloan Roach said.
Nassir Harris will start his new job Monday, with the condition that he passes the test.
"No one should have to go through this," Anita Harris said.
WSB-TV asked Roach if she had ever heard of any other situation like this. She said she hadn't.