Friday, a judge sentenced 21-year-old David Aranda Hernandez to 50 years to life behind bars.
Hernandez, who was extradited from Mexico last year, was convicted of shooting and killing 16-year-old Edward Satterstrom as he walked along Laurel Canyon Boulevard in Sun Valley in 2008.
Prosecutors say Hernandez shot Satterstrom twice in the back after making a gang challenge.
