Some of those in the crowd wore white T-shirts bearing a picture of the young toddler who died in what appeared to be a botched hijacking.
Morris died in July after being dragged for a long distance behind the hijacked car.
The words “Genoeg is genoeg” (enough is enough) were printed on the T-shirts.
The crowd, which included the toddler’s family and community members, gathered around a blue Mercedes Benz where others were handed T-shirts.
They formed a circle and prayed outside the court.
“It has been three months of crying… We are here to thank God for the arrest of this man. We’ve been waiting for this,” said one man in the crowd.
They began singing and chanting outside the court.
The suspect was arrested on Tuesday.
“The suspect was arrested in Katlehong and was positively identified as one of the hijackers who hijacked the family while visiting a relative on the day,” said Colonel Noxolo Kweza.
He was in a VW Golf with his mother, father, and sister in Reiger Park, when three men approached them.
The men ordered the family out of the vehicle. Taegrin was left hanging halfway out of the car in his safety belt and was dragged as the car was driven off by the hijackers.
He was found dead in Boksburg, between eight to 10km away.
Kweza said the man had been charged with murder and hijacking.