Zimmerman, a former neighborhood watch volunteer, has pleaded not guilty to second-degree murder and says he shot the unarmed 17-year-old Martin in self-defense during a scuffle in the townhouse complex.
Among the first to publicize the story was nationally syndicated radio host Michael Baisden, who sent a message to his 65,000 Twitter followers and 585,000 Facebook fans: "Unarmed 17-year-old boy shot by neighborhood watch captain in Sanford, FL outside of Orlando." It provided a link to a story. Soon afterward, Martin's parents started an online petition on Change.org demanding Zimmerman's arrest. It generated more than 2.2 million signatures.
The trial began with attorneys' scouring potential jurors' profiles, using Facebook postings to keep two off the jury. Witnesses haven't been immune, either, a fact Zimmerman's lead defense attorney recently acknowledged.
"So it's been an amazing sort of umbrella in this case," attorney Mark O'Mara recently told reporters, "the whole sort of social media presence and what it means both in investigation to interaction to now having to react to it as lawyer."
Those involved in the Zimmerman case appear to have been tripped up by social media on at least two occasions.
While questioning Jenna Lauer, a former neighbor of Zimmerman who testified she heard screams for help outside her townhome, Prosecutor Bernie de la Rionda accused her of following Zimmerman's brother on Twitter. After taking a look at a Twitter page de la Rionda had pulled up on a computer, Lauer had to explain to him that it was Zimmerman's brother following her.
"I apologize," de la Rionda said.
On the defense side, an Instagram photo posted by attorney Don West's daughter became the subject of a prosecution motion for an inquiry. Prosecutors said the photo showing West eating ice cream with his daughters was posted after West's tense cross-examination with prosecution witness Rachel Jeantel last week. The caption read, "We-beat-stupidity celebration cones" and "dadkilledit." West said in a court filing Tuesday that the photo was taken a day before Jeantel testified and that it had nothing to do with her testimony.