Jonathan Fajardo showed no emotion when the judge sentenced him to death and over 200 years in prison.
"I tried to have some compassion for him, but ... he's like a monster," said Charlene Lovett, Green's mother.
Last September, a jury found the 22-year-old guilty of first-degree murder in the December 2006 shooting death of the eighth grader. Fajardo, 18 at the time, opened fire on a group of blacks in the Harbor Gateway area.
Police say that he targeted the group because they were black. The killing sparked an outcry of protest from community members and elected officials.
"I thought those days were over with," Lovett said.
Fajardo was also convicted and sentenced to death for the stabbing death of 25-year-old Christopher Ash, a potential witness, nearly two weeks after Green's murder.
Fajardo was eligible for the death penalty on the special circumstance of multiple murder, committing a hate crime basd on race and committing the crime for a gang. Authorities say he is a part of the 204th Street gang.
The victim's family said they are relieved that justice has finally been served.
"She'll always be with us, and I'm just glad that this part is over with," said the victim's grandmother Marlene Townes. "We can finally move forward."