In May 2012, the defense received the first round of discovery evidence: 67 compact discs, a list of witnesses that included 50 possible law enforcement officers, 28 officers from the Sanford Police Department, 28 civilian witnesses, members of Martin's family, two of Zimmerman's friends and his father, Robert Zimmerman.
In June 2012, the prosecution released recordings of two 911 calls placed by Martin's father the morning after the shooting.