For instance, a friend who was on the phone with Martin at the time told authorities the teen told her he was being followed. Zimmerman has since said he wasn't pursuing Martin. Rather, he was trying to determine a good street address to give to police.
Another example is the shooting itself. While Zimmerman's opponents say he had no cause to shoot Martin, 911 calls indicate there was a struggle that was loud enough to alert neighbors in the townhome community.
Someone is heard shouting for help -- accounts vary as to who -- then, on one of the calls, a gunshot is heard.
Zimmerman said it was Martin who attacked him, decking him with a punch to the nose before slamming his head repeatedly into the sidewalk. The first images released of Zimmerman -- from a grainy surveillance video -- didn't seem to support the assertion. He seemed clean, uninjured even, many said.
But color photos released later -- one of the back of Zimmerman's skull streaked in blood and another showing Zimmerman's swollen nose, blood smeared across his mustache and lip -- raised the possibility he may have been attacked.
"If people claim you attacked and held him down and shot him you wouldn't be injured but you are. That proves to me your story makes more sense," read an e-mail from one supporter.
Other observers were not convinced.
"Your bloody nose picture only shows that Martin was fighting for his life against an armed man," a retired Florida police officer wrote.
Claiming self-defense, Zimmerman wasn't arrested immediately. That decision by local police prompted many protests. Thousands rallied and walked out of schools.
A specially appointed prosecutor decided to charge Zimmerman with second-degree murder in April, more than six weeks after the shooting, and the Sanford city manager axed Police Chief Bill Lee in June.
Now, his defense team is faced with the task of convincing Seminole County Judge Debra Nelson that Zimmerman feared for his life. Many letters to Zimmerman indicate there are plenty of people who have already made up their minds.
"I believe you did what you needed to do I don't don't (sic) think you were wrong you were trying to protect yourself," read an e-mail."
"The fact is that Trayvon physically assaulted another human being, and in a civilized society, you aren't allowed to do that," said another supporter.
Other letters, however, cast Zimmerman as a coward who shot a teen after picking a fight with him.
"You shot trayvon when you were losing to (sic) fight that you started!" one such e-mail chastised Zimmerman.
It continued, "Think about your nieces and nephews what if they were being followed by a strange male and turned to confront them, got in a fight with them got killed and the man said it was self-defense. May God bless your soul, if you can't see what you did was wrong."
Nelson will decide in April whether Zimmerman can avoid prosecution during an immunity hearing dealing with Florida's now-controversial stand-your-ground law.
The law states that people can use deadly force to defend themselves if they believe they are threatened with death or serious bodily harm. Though Martin's supporters question how the law can be invoked under the circumstances in this case, there are those who believe the neighborhood watchman handled himself appropriately.
"Thank you for standing your ground," one note said.
If Nelson agrees with the stand-your-ground claim, Zimmerman's scheduled June trial will be called off. If she rules against it, the trial will proceed.
While many people have steadfast opinions about what happened the night Martin was killed, there are those who feel the situation is still unclear.
"I don't know what actually happened between the two of them. In my 'gut,' I feel it was probably a tragic accident and that they were both in the wrong place at the wrong time," read a handwritten letter.
Another stated, "I do not think that you are a racist, just a loose cannon from the 19th century. ... I do not hate you or like you, I am pretty much neutral."
If Nelson sends the case to trial, the next stage will be jury selection. If these last few letters are any indication, there may still be at least a few impartial onlookers amid a sea of passionate opinions.