Zimmerman's family seemed relieved Zimmerman is now in custody. His brother Robert Zimmerman told CNN's Piers Morgan Wednesday night, "The only silver lining in all of this is that my brother is safe. For our family that's the only rest that we'll get tonight when we lay our heads down to sleep is that we'll know that our brother is safe."
Martin's parents talked about the arrest today on "GMA."
"There were tears, but they were tears that I was satisfied with her (Corey's) decision," Martin's mother Sybrina Fulton said.
" We have a sense of peace right now because we know that the person that shot and killed our son will be held accountable for it. We can't really say what the outcome will be, but we have committed to this journey," Fulton said.
The teen's dad, Tracy Martin, said he wants "to hear the truth from him."
The U.S. Justice Department is also carrying out an investigation into the shooting. Attorney General Eric Holder indicate today that the feds will have a higher bar to establish that the shooting was a hate crime.
"For a federal hate crime we have to prove the highest standard in the law it is something that was reckless, that was negligent ... We have to show that there was a specific intent to do the crime with the requisite state of mind," Holder said.
ABC News' Aaron Katersky contributed to this report