February 26, 2012 – George Zimmerman, a neighborhood watch captain in Sanford, Fla., calls 911 to report “a suspicious person” in the neighborhood. He is instructed not to get out of his SUV or approach the person. Zimmerman disregards the instructions. Moments later, neighbors report hearing gunfire. Zimmerman acknowledges that he shot Martin, claiming it was in self-defense. In a police report, Officer Timothy Smith writes that Zimmerman was bleeding from the nose and back of the head.

February 27, 2012 - Martin's father, Tracy Martin, files a missing persons report. Officers with the Sanford Police Department visit Tracy Martin. He is able to identify Trayvon Martin's body using a photo.

March 8, 2102 - Investigators receive a fax from the Altamonte Family Practice containing the medical records identifying the injuries sustained by Zimmerman on the night of the shooting: Open wound of scalp, without mention of complication; nasal bones, closed fracture; assault by other specified means.

March 12, 2012 - Sanford Police Chief Bill Lee says that Zimmerman has not been charged because there are no grounds to disprove his story of the events.

March 13, 2012 - Sanford Police Department's homicide detective Christopher Serino recommends Zimmerman be charged with manslaughter. 
Zimmerman "failed to identify himself" as a concerned citizen or neighborhood watch member on two occasions that night. Serino reports that he thought Zimmerman's head injuries were "marginally consistent with a life-threatening episode, as described by him, during which neither a deadly weapon nor deadly force were deployed by Trayvon Martin."

March 14, 2012 - The case is turned over to the Florida State Attorney Norm Wolfinger.

March 15, 2012 - In a letter to the Orlando Sentinel, Robert Zimmerman, George Zimmerman's father, writes that George has been unfairly portrayed as a racist, and that George is Hispanic and grew up in a multiracial family.

March 16, 2012 - Authorities release seven 911 calls from the night of the shooting. In one of the 911 recordings, Zimmerman, against the advice of the 911 dispatcher, follows Martin. In one of the recordings, a voice screams "Help, help!" in the background, followed by the sound of a gunshot.

March 19, 2012 - The Justice Department and the FBI announce that they have launched an investigation into Martin's death.

March 20, 2012 - A lawyer for the Martin family, Benjamin Crump, holds a news conference, telling reporters that Trayvon was on the phone with his 16-year-old girlfriend at the time of the shooting. The girl, who wishes to remain anonymous, says she heard someone ask Martin what he was doing and heard Martin ask why the person was following him, according to Crump. The girl then got the impression that there was an altercation in which the earpiece fell out of Martin's ear and the connection went dead.

March 21, 2012 - CNN analyzes one of the tapes of Zimmerman's call to dispatch, in which he is purported to have used a racial slur against blacks. The results are inconclusive.

March 22, 2012 - A petition on calling for the arrest of Zimmerman, created by the parents of Trayvon Martin, surpasses 1.3 million people.

March 22, 2012 - Sanford Police Chief Bill Lee announces he is stepping down "temporarily" as head of the department, which has been criticized for its handling of the fatal shooting.

March 22, 2012 - Florida Gov. Rick Scott announces he is appointing Angela B. Corey of the 4th Judicial Circuit as state attorney in the investigation, replacing Norman Wolfinger, state attorney for Florida's 18th District, which includes Sanford.

March 23, 2012 - President Barack Obama speaks out publicly for the first time on the growing controversy over the shooting of Trayvon Martin, saying that the incident requires national "soul-searching."

March 24, 2012 - A handful of members from the New Black Panther Party (NBPP) offer a $10,000 reward for the "capture" of George Zimmerman.

March 26, 2012 - Exactly one month after Trayvon Martin's death, rallies take place in cities across the country, including Sanford, where the City Commission holds a town hall meeting on the incident and its aftermath. Martin's parents speak at the meeting.

March 28, 2012 - Zimmerman's father, Robert, appears on television and says that Martin threatened to kill Zimmerman and then beat him so badly Zimmerman was forced to shoot.

March 29, 2012 - Zimmerman's brother, Robert Zimmerman Jr., appears on CNN and says medical records will prove that his brother was attacked and his nose was broken by Trayvon Martin before he fatally shot the teen.

April 2, 2012 - FBI agents interview Martin's girlfriend, the 16-year-old girl who, phone records show, was on the cell phone with him shortly before the fatal confrontation.

April 3, 2012 - Zimmerman's legal adviser, Craig Sonner, says that criminal defense lawyer Hal Uhrig will represent Zimmerman and that Sonner will serve as co-counsel if the case proceeds.

April 7-8, 2012 - George Zimmerman launches a website warning supporters about groups falsely claiming to be raising funds for his defense. The site includes a link through which donations can be made to pay for Zimmerman's lawyers and living expenses.

April 9, 2012 - Prosecutor Angela Corey announces that she will not present the case to a grand jury.

April 10, 2012 - Attorneys Hal Uhrig and Craig Sonner announce that they have lost contact with Zimmerman and no longer represent him.

April 11, 2012 - Zimmerman is charged with second-degree murder. His new lawyer, Mark O'Mara, tells CNN that Zimmerman has turned himself in.