"There will be a federal investigation. They will publicly discuss it. The civil rights division will not file. " Abrams said. "They won't win, and they know that."
Police departments across south Florida had been braced for possible violence in response to the acquittal, but while reaction in social media has been heated the handful of protests in San Francisco, Los Angeles and Atlanta were muted and peaceful.
But in Oakland, Calif., about 100 demonstrators took to the streets, smashing the windows of businesses, starting small fires in the streets, and vandalizing a police car, the Associated Press reported.
Benjamin Crump, a lawyer for the Martin family, acknowledged the disappointment of Trayvon Martin's supporters, but he urged them not to resort to violence.
"For Trayvon to rest in peace, we must all be peaceful," Crump said.
ABC News' Shushannah Walshe contributed to this report