SANFORD, Fla. — The families of George Zimmerman and Trayvon Martin are reacting on Twitter after the former neighborhood watch volunteer was cleared of all charges in the fatal shooting of the unarmed black teen.

Zimmerman's brother, Robert Zimmerman Jr., says his family is relieved that the jury found George Zimmerman not guilty of second-degree murder and manslaughter. He tweeted: "Today ... I'm proud to be an American."

Martin's parents, Tracy Martin and Sybrina Fulton, were reserved but expressed their disappointment. Fulton expressed her faith in God, saying "Lord during my darkest hour I lean on you." Tracy Martin tweeted that he was broken-hearted, but that his faith is "unshattered."

The teen's brother, Jahvaris Fulton, said simply: "Et tu America?" — a reference to the Latin phrase "Et tu, Brute?" known as an expression of betrayal.