Los Angeles Superior Court Judge Ronald H. Rose agreed with the jurors' recommendation for the death sentence. Rose did not take the option to reduce the sentence to life in prison without the possibility of parole.
At the sentencing hearing, Pedro Espinoza heard directly from the victim's family members.
"The days when I was growing up, it was basically, you use your fists. You don't just go and kill somebody cold blood. It's the coward's way out," said uncle Hector Davis.
Shaw was a football standout who Espinoza shot thinking he was a rival gang member. Before the judge pronounced the death penalty, the Shaw family told of their pain, still raw after four years.
"I'm not that strong of a Christian because I can't turn around and say I forgive you for killing my son," said mother Anita Shaw.
Espinoza, 23, was found guilty of first-degree murder back in May. He is an undocumented immigrant and had a history of gang crime and assaults while behind bars. He shot Shaw a day after he had been released from jail in March 2008.
In a last-ditch effort to avoid sentencing, Espinoza demanded a new trial, telling the judge his attorney was incompetent. The motion was denied, with the judge saying the circumstantial evidence in the case was overwhelming.
The 17-year-old standout running back was killed by Espinoza for carrying a red Spider-Man backpack. Prosecutors say Espinoza, who was a member of the 18th Street Gang, perceived the color of the backpack as linking Shaw to an opposing gang.
Shaw was not a gang member. The teen, who had a collection of Spider-Man items, was walking home when he was shot once in the abdomen and once in the head. His mother was an Army officer serving in Iraq when the shooting occurred.
Shaw's murder sparked a campaign for "Jamiel's Law," aimed at rounding up gang members who are in the U.S. illegally. The measure won support from conservatives but failed to get enough signatures to get on the ballot.