"I hope you man up and take responsibility for what you did," Robinson said.
On Wednesday, Royster was also sentenced to life in prison. He was put in handcuffs and taken away.
Outside the courthouse, Amias' mother said that the verdict is the beginning of the healing process.
"There's finally a murderer, a predator off the streets and I think everyone else can sleep good tonight," said Arimisher Glenn, the victim's mother.
Not everyone agrees. A woman who identified herself as the mother of Royster's child told Eyewitness News that she thinks Royster is innocent.
"If they feel like they got justice then OK, I don't have nothing to say about that. But like I said, at the end of the day, Ellis didn't do that. Period," she said.
Royster's defense attorney told Eyewitness News that he was surprised by the verdict. He referred to the fact another man was initially arrested for the murder, then later let go.
"I thought the people who actually saw what happened, gave their statement within 12 hours, probably were more truthful than the people who had two months to decide what they were going to say," said defense attorney Richard Tomberlin.
Royster's attorney told Eyewitness News that he will be appealing this conviction.