The brief outline, contained in an affidavit filed in support of the second-degree murder charges, appeared to contradict Zimmerman's claim that Martin attacked him after he had turned away and was returning to his vehicle.
In the affidavit, prosecutors also said that Martin's mother identified cries for help heard in the background of a 911 call as her son's. There had been some question as to whether Martin or Zimmerman was the one crying out.
The account of the shooting was released as Zimmerman, 28, appeared at a four-minute hearing in a jailhouse courtroom, setting in motion what could be a long, drawn-out process, or an abrupt and disappointingly short one for the Martin family because of the strong legal protections contained in Florida's "stand your ground" law on self-defense.
During the hearing, Zimmerman stood up straight, held his head high and wore a gray jail jumpsuit. He spoke only to answer "Yes, sir" twice after he was asked basic questions from the judge, who was not in the courtroom but on closed-circuit TV. The defendant's hair was shaved down to stubble and he had a thin goatee. His hands were shackled in front of him.
He did not enter a plea; that will happen at his arraignment, which was set for May 29. Zimmerman's attorney, Mark O'Mara, has said his client will plead not guilty. A bail hearing for Zimmerman probably will be held April 20, O'Mara said late Thursday.
To prove second-degree murder, prosecutors must show that Zimmerman committed an "imminently dangerous" act that showed a "depraved" lack of regard for human life. The charge carries a mandatory sentence of 25 years in prison and a maximum of life.
The special prosecutor in the case, Angela Corey, has refused to explain exactly how she arrived at the charge. But in the affidavit, prosecutors said Zimmerman spotted Martin while patrolling his gated community, got out of his vehicle and followed the young man.
Prosecutors interviewed a friend of Martin's who was talking to him over the phone moments before the shooting. His parents' lawyer has said that Martin was talking to his girlfriend back in Miami.
"During this time, Martin was on the phone with a friend and described to her what was happening," the affidavit said. "The witness advised that Martin was scared because he was being followed through the complex by an unknown male and didn't know why."
During a recorded call to a police dispatcher, Zimmerman "made reference to people he felt had committed and gotten away with break-ins in his neighborhood. Later while talking about Martin, Zimmerman stated `these a------s, they always get away' and also said `these f-----g punks,' said the affidavit, available at http://apne.ws/Itn7Nu .
It continued: "When the police dispatcher realized Zimmerman was pursuing Martin, he instructed Zimmerman not to do that and that the responding officer would meet him. Zimmerman disregarded the police dispatcher and continued to follow Martin who was trying to return to his home."
"Zimmerman confronted Martin and a struggle ensued," prosecutors said in their account.
The account provided no details on the struggle other than to say that witnesses heard numerous calls for help and that Martin's mother reviewed the 911 recordings and recognized her son's cry.
Zimmerman told authorities that Martin attacked him as he going back to his vehicle, punched him in the face, knocked him down and began slamming head against the sidewalk.
At Thursday's hearing, the case was assigned to Circuit Judge Jessica Recksiedler, a 39-year-old former assistant state attorney from Sanford who was elected to the bench in 2010. Zimmerman is being held without bail at the county jail.
For all the relief among civil rights activists over the arrest, legal experts warned there is a real chance the case could get thrown out before it ever goes to trial because of Florida's "stand your ground" law, which gives people a broad right to use deadly force without having to retreat from a fight.
At a pretrial hearing, Zimmerman's lawyers would only have to prove by a preponderance of evidence -- a relatively low legal standard -- that he acted in self-defense in order to get a judge to toss out the second-murder charges. And if that fails and the case does go to trial, the defense can raise the argument all over again.
There's a "high likelihood it could be dismissed by the judge even before the jury gets to hear the case," Florida defense attorney Richard Hornsby said. Karin Moore, an assistant professor of law at Florida A&M University, said the law "puts a tremendous burden on the state to prove that it wasn't self-defense."
At some point soon, Zimmerman's lawyer is expected to ask the judge for a hearing on "stand your ground."
"It is going to be a facet of this defense, I'm sure," O'Mara said in an interview. "That statute has some troublesome portions to it, and we're now going to have some conversations and discussions about it as a state. But right now it is the law of Florida and it is the law that is going to have an impact on this case."
Martin family and their lawyer acknowledged the arrest is just a first step.
"I think that it will start the process that we are pushing for," said Martin's father, Tracy Martin, "but we can't just stop because we have an arrest. We got to keep pushing to get a conviction, and after a conviction we have to certainly continue to push to get a stiff sentence."
Martin family attorney Ben Crump said he wants to make the repeal or the amending of "stand your ground" laws in Florida and other states to be a big part of Trayvon Martin's legacy. "We're not the wild, wild west," Crump said.
As for Zimmerman, O'Mara said after the court appearance: "He is tired. He has gone through some tribulations. He is facing second-degree murder charges now. He is frightened. That would frighten any of us."
"He has a lot of hatred focused on him right now," the defense attorney said. "I'm hoping that the hatred settles down now that we're moving forward."