A teenager convicted of killing two people in Reading learned his fate Thursday.

Matthew Perkins, 18, received a sentence of 20 to 40 years in prison.

Earlier this month, a jury convicted Perkins of third degree murder for the killing of 22-year-old Cesar Rivera.

Rivera's mother, Cira, was infuriated by the sentence, saying it wasn't enough.

"I'm afraid that he'll get out and do the same thing to someone else," Cira said in Spanish outside the Berks County Courthouse.

Perkins was also convicted of third-degree murder for the death of Juan Perez Pimentel.

For six months Pimentel was transferred to several hospitals as his fought for his life, only to finally succumb to his injures, court officials said.

Pimentel's family was not in court, but Cira Rivera spoke on their behalf.

"They were two human beings he [Matthew Perkins] killed, not two rats in the street, so to give him only 20 to 40 years just isn't fair," Cira said.

The crime happened in July 2011 on Heckman's Court, an alley near 11th and Mulberry streets in Reading, police said.

The altercation was sparked after a fight that ensured during a late-night party, officials said.

"I recognize the jury rejected self-defense," Judge James Bucci explained. "Nevertheless, the evidence showed that the defendant [Matthew Perkins] was clearly being pursued by multiple people; that the defendant gave his assailants a warning: 'Don't move;' that defendant fled, ran, and that multiple men continued to pursue him. All of this mitigates the defendant's culpability."

Court officials say, after the shooting, Perkins fled to Florida where he was later arrested.

"There's no medicine that can cure the pain that I feel in my heart," Cira Rivera said. "This pain can only be alleviated by God."

Judge Bucci says that when Matthew Perkins gets out of jail he will still be on probation for an additional 20 years.