Fifteen facts we should know about Trayvon Martins

From Think Progress: On February 26, 2012, a 17-year-old African-American named Trayvon Martin was shot and killed in Sanford, Florida. The shooter was George Zimmerman, a 28-year-old white man. Zimmerman admits killing Martin, but claims he was acting in self-defense.

Three weeks after Martin's death, no arrests have been made and Zimmerman remains free.

Here is what everyone should know about the case:

1. Zimmerman called the police to report Martin's "suspicious" behavior, which he described as "just walking around looking about."

Zimmerman was in his car when he saw Martin walking on the street. He called the police and said: "There's a real suspicious guy. This guy looks like he's up to no good, on drugs or something. It's raining and he's just walking around looking about... These a**holes always get away" [Orlando Sentinel]

2. Zimmerman pursued Martin against the explicit instructions of the police dispatcher:

Dispatcher: "Are you following him?"
Zimmerman: "Yeah"
Dispatcher: "OK, we don't need you to do that."

[Orlando Sentinel]

3. Prior to the release of the 911 tapes, Zimmerman's father released a statement claiming "[a]t no time did George follow or confront Mr. Martin." [Sun Sentinel]

4. Zimmerman was carrying a a 9 millimeter handgun. Martin was carrying a bag of Skittles and a can of iced tea. [ABC News]

5. Martin weighed 140 pounds. Zimmerman weighs 250 pounds. [Orlando Sentinel; WDBO]

6. Martin's English teacher described him as "as an A and B student who majored in cheerfulness." [Orlando Sentinel]

7. Martin had no criminal record. [New York Times8. Zimmerman "was charged in July 2005 with resisting arrest with violence and battery on an officer. The charges appear to have been dropped." [Huffington Post]

9. Zimmerman called the police 46 times since Jan. 1, 2011. [Miami Herald]

10. According to neighbors, Zimmerman was "fixated on crime and focused on young, black males." [Miami Herald]

11. Zimmerman "had been the subject of complaints by neighbors in his gated community for aggressive tactics" [Huffington Post]

12. A police officer "corrected" a key witness. "The officer told the witness, a long-time teacher, it was Zimmerman who cried for help, said the witness. ABC News has spoken to the teacher and she confirmed that the officer corrected her when she said she heard the teenager shout for help." [ABC News]

13. Three witnesses say they heard a boy cry for help before a shot was fired. "Three witnesses contacted by The Miami Herald say they saw or heard the moments before and after the Miami Gardens teenager's killing. All three said they heard the last howl for help from a despondent boy." [Miami Herald]

14. The officer in charge of the crime scene also received criticism in 2010 when he initially failed to arrest a lieutenant's son who was videotaped attacking a homeless black man. [New York Times]

15. The police did not test Zimmerman for drugs or alcohol. A law enforcement expert told ABC that Zimmerman sounds intoxicated on the 911 tapes. Drug and alcohol testing is "standard procedure in most homicide investigations." [ABC News]

The Martin case had been turned over to the Seminole County State Attorney's Office. Martin's family has asked for the FBI to investigate.