Key Players: Robert Zimmerman Sr.

Published On: Apr 18 2013 02:12:32 PM EDT   Updated On: Apr 19 2013 12:48:27 PM EDT

Age: 64

Background: George Zimmerman's father. He served in Vietnam as part of the U.S. Army and retired after 21 years.

Involvement in the case: Zimmerman Sr. has often spoken out against the media's portrayal of his son as the villain. He claims that Trayvon attacked his son, who acted in self-defense. He and his wife, Gladys, started an online fund to help pay for his medical expenses and their relocation efforts.