George Zimmerman leaves the courtroom a free man after being found not guilty in the 2012 shooting death of Trayvon Martin. Reuters/Joe Burbank

One of the jurors who acquitted George Zimmerman told CNN Monday she believed Trayvon Martin threw the first punch and that Zimmerman feared for his life before shooting him.

The juror, identified only as B37, who spoke on the condition of anonymity, talked to CNN's "Anderson Cooper 360" Monday night.

She claimed to have no idea of the trial’s national prominence. “I didn’t see it as a racial thing. I saw it as a murder case.”

The juror also said she believed Zimmerman's "heart was in the right place" the night he killed Martin, but didn't use "good judgment" in confronting him. She also was persuaded it was Zimmerman's voice that was heard screaming for help in 911 calls.

“He had a right to defend himself,” she said. “That’s how we read the law.”

“I had no doubt George feared for his life at the time in the situation he was in,” she said later.

She found both men in part responsible for the “tragedy” of Martin's death. “Both could have walked away.”

The juror also said she found prosecution witness Rachel Jeantel, who was talking to Martin on the phone at the time of the fatal fight, “not credible” but “felt sorry” for her.

She said an initial poll of the jurors had three believing Zimmerman not guilty, one guilty of second-degree murder, and two guilty of manslaughter. Some jurors wanted to find Zimmerman “guilty of something” but were persuaded that the law did not allow such a verdict.

She said, tearfully, that jurors cried when they reached their decision. “We thought about it for hours and cried over it afterwards.”

The juror will be writing a book about her experiences, literary agent Sharlene Martin told CNN.

"My hope is that people will read Juror B37's book, written with her attorney husband, and understand the commitment it takes to serve and be sequestered on a jury in a highly publicized murder trial and how important, despite one's personal viewpoints, it is to follow the letter of the law," the president of Martin Literary Agency wrote in a statement.

"It could open a whole new dialogue about laws that may need to be revised and revamped to suit a 21st Century way of life," Martin said.

Jurors were not identified by name during the trial. But according to HLN, CNN's sister network, juror B37 has been married 20 years, has two adult children and once had a concealed weapons permit.