(CNN) - President Barack Obama said Friday that "Trayvon Martin could have been me 35 years ago" in his first live comments since a Florida jury acquitted George Zimmerman last weekend in the teenager's shooting death.
He also said protests over the verdict should remain nonviolent.
The president said Americans are aware of the "history of racial disparity in our criminal laws" and said the government should review some state and local legislation, such as Florida's "stand your ground" law, saying they may promote rather than discourage violent confrontations.
A jury acquitted Zimmerman last Saturday in Martin's February 26, 2012, shooting death, inciting anger among many who considered the incident racially motivated murder.
Obama issued a written statement on Sunday noting that the jury had spoken and urging calm and reflection.
On Friday, he also said successive generations of Americans have gotten better at changing attitudes on race, but "we have to be vigilant and work on these issues."
To demonstrators calling for federal civil rights charges against Zimmerman, Obama said they must "have some clear expectations here."
He stressed that law enforcement and the criminal code "is traditionally done at the state and local levels, not at the federal level."