George Zimmerman is charged with the murder of teenager Trayvon Martin. (13676)

SANFORD, Fla. — On the first day of the George Zimmerman trial, four-letter words went over a lot better than a knock-knock joke — at least among trial-watchers. What the actual jurors thought of each side’s opening statement is, of course, far more significant, but also unknown.

If keyboard-pounding Twitter users are any indication, however, George Zimmerman’s defense team may already be facing an uphill battle.

People on the social media site quickly rendered their own verdict Monday — overwhelmingly in favor of the prosecution, which opened its case repeating Zimmerman’s own expletive-laced words from the night of Trayvon Martin’s death.

Meanwhile, defense attorney Don West’s knock-knock joke fell flat. Leading up to the trial, Zimmerman supporters have been very active and vocal on social media in their defense of the former neighborhood watchman, making Monday’s shift that much more interesting.

“Great”, “perfect” and “effective” were among the terms used by HLN’s Twitter followers when asked to describe the prosecution’s opening in one word. Some also went with “boring” and “lullaby.”

Reflecting the general tone of Twitter’s virtual jury, one-word responses such as “embarrassing,” “painful,” “messy” and “clumsy” were attached to West’s presentation by HLN’s followers.

Much of the criticism of the defense’s opening was pegged to West’s joke, which was delivered early on and seemed to leave a bad impression.

The joke — “Knock knock. Who’s there? George Zimmerman. George Zimmerman who? Good, you’re on the jury” failed to win a laugh from anyone on the jury.

Here’s a representative sample of the observations and reactions to the opening statements that were shared Monday on Twitter:

• “I don’t recall hearing a single reference to black, white, African-American or race in Guy’s opening.”

• “The objection sustained for personalizing opening really threw Don West off, led him to tell awkward knock knock joke.”

• “Zimmerman’s lawyer starts opening remarks with a knock-knock joke. So they’re already shooting for “incompetent counsel” in the appeal.”

• “To all of those that donated to the GZ defense fund: This is how your $$ was spent. Wow.”

• “Certainly first high profile murder case I’ve covered where one side led with an expletive and the other told a knock knock joke.”

• “Zimmerman defense is offering a near-seamless opening statement, rolling from one bit of evidence to another without gaps.”

• “If you have to say to the jury ‘I don’t know if you’re following me or not’ that is pretty pathetic.”

After the opening statements, four witnesses made their way to the stand Monday afternoon.

Court was recessed early after the defense objected to prosecutors playing a 911 call made by George Zimmerman in August, 2011. The issue will be discussed first thing when attorneys arrive back in court Tuesday at 8:30 a.m. ET.

Jonathan Anker |