Espinoza's gang affiliation makes him eligible for the death penalty. He was also reportedly in the country illegally when he murdered Shaw. The prosecution is seeking the death penalty with the support of Shaw's family.
For three days, probation officers and jail personnel described Espinoza as a persistent troublemaker, attacking other inmates and deputies more than a dozen times.
His defense team says Espinoza was neglected and abused as a child. That's a stark contrast to how Shaw, 17, was raised.
Jamiel Shaw II was gunned down just three doors away from his Arlington Heights home after leaving a friend's house in 2008. He was confronted by Espinoza, who thought he was a member of a rival gang.
Shaw had been attracting attention for his athletic talents from schools like Rutgers and Stanford at the time of his death.
The parents say the death penalty for Espinoza is justified, and ask that it be done without years of delay.
Shaw's mother Anita, an Army sergeant, was in Iraq when she was notified of her son's death.
"He came in and he killed him quickly, so let his death be quickly," said Shaw. "Listen to all the stuff that he has done while my son was doing nothing but good. His life speaks for what he deserves. He's guilty. He deserves death."