Actor and activist Mark Ruffalo, far left, Cornell University engineering professor Anthony Ingraffea and Sean Lennon listen as Yoko Ono speaks during a press conference to launch a coalition of artists opposing hydraulic fracturing on Aug. 29, in New York.
Zimmerman's trial began on June 10, 2013, in Sanford. On July 13, 2013, a jury acquitted him of second-degree murder and of manslaughter charges.