In a video posted online, the 63-year-old singer told the crowd Tuesday: "We'll send this as a letter back home for justice for Trayvon Martin" after noticing a fan's sign that read "American Skin (41 Shots)."
George Zimmerman was acquitted Saturday of second-degree murder and manslaughter charges in Martin's death. Zimmerman said he fired his gun in self-defense during a February 2012 confrontation with the 17-year-old in Sanford, Fla.
Lyrics in the song include "you can get killed just for living in your American skin." Springsteen wrote the song about the 1999 police shooting death of Guinean immigrant Amadou Diallo.