Many of them went wearing buttons and blue ribbons because it was his favorite color.
His parents are still struggling to understand why he was killed, as police announced a fifth arrest in his murder.
“Every morning I wake up, I pray it's a nightmare. I hope it's a nightmare,” the boy’s mother, Adrienne Rodriguez, said.
Rodriguez, along with other family and friends, attended Carrollton High School's football game Friday night, where the crowd honored Nizzear with signs and t-shirts.
His 16-year-old uncle plays on the team that remembered Nizzear before kick-off.
Carrollton police say the teen was asleep in his bed, just hours after celebrating his 13th birthday, when Malik Davis and Kenneth Wheat went inside the home and shot Nizzear.
“I don't even care what the story is to be honest. They didn't take anything so they can say they came in to do whatever but they killed my son,” Rodriguez said.
Investigators say they do not know the motive but say it is possible Davis and Wheat were in the wrong apartment.
Kaheel Balson said both suspects had been at the home before and had even been fed by Nizzear's grandmother.
“If you're at their house every day, you know that's my son's house, you know that's my son's room,” Balson said.
On Friday, police arrested Britannica Turner with giving false information. Oleda Ward is charged with the same crime. Police also arrested Jackquiline Freeman, who they believe drove the getaway car.
The family says they do not know why anyone would want to hurt Nizzear, who was a straight-a student with no enemies.
His wake is planned for next Friday and his funeral will be held Saturday, both at the Tabernacle Church in Carrollton.