The star prosecution witness in the murder trial of George Zimmerman took the stand to recount her cell phone conversation with Trayvon Martin in the moments before he was shot to death, saying the Florida teen said he was being followed by “a creepy-ass cracker” just before the fatal confrontation.

Rachel Jeantel, 19, told jurors she warned Martin to walk away, saying "it might be a rapist." Martin, she said, told her he was going to try to "lose him" and get to his father's fiance's home in the gated community in Sanford. But Jeantel said as she remained on the phone with Martin, the man who was allegedly following him reappeared, prompting the February, 2012 confrontation, of which she heard the initial moments.

"He said, "Why are you following me for?", and then I heard a hard breathed man come and say "What are you doing around here?".

Jeantel testified she heard Martin's phone headset fall and then Martin say "Get off!" The phone went dead shortly after and Jeantel says she didn’t speak to Martin again.

Previously, Jeantel came under fire for lying about not going to Martin’s funeral because she said she was in the hospital, which was untrue. In her testimony Wednesday, she said she didn’t go because she felt guilty.

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Martin's parents have said they believe the cries for help heard by neighbors came from their son, while Zimmerman's father believes the cries belong to his son. Both prosecutors and defense attorneys believe they could show whether Zimmerman or Martin was the aggressor in the encounter. Defense attorneys successfully argued against allowing prosecution experts who claimed the cries belonged to Martin.

Jeantel testified that she believed the cries were Martin's because "Trayvon has kind of a baby voice." Defense attorney Don West challenged that, claiming she was less certain in a previous deposition.

Jeantel also explained that she had initially lied about her age -- she claimed to be 16 -- to protect her privacy when she was initially contacted by an attorney for Martin's family to give a recorded statement over the telephone about what she knew about the few moments before Martin's encounter with Zimmerman. She was expected to finish her testimony on Thursday at 9 a.m.

While being cross-examined, Jeantel had several testy exchange with West, including one moment when she prompted the defense attorney to ask his next question: "You can go. You can go."

At one point, Judge Debra Nelson had to calm Jeantel down.

SPECIAL COVERAGE: ZIMMERMAN TRIAL

Earlier Wednesday, jurors heard audio recordings of five non-emergency calls Zimmerman made to police in the months before the 2012 confrontation with Martin. Zimmerman, 29, who is charged with second-degree murder, called the police close to 50 times over an eight-year period to report such things as slow vehicles, loitering strangers in the neighborhood and open garages.

Prosecutors say the dozens of calls show Zimmerman’s overzealousness in pursuing people he considered to be suspicious -- and his state of mind on the night he shot unarmed teen.

The recordings show Zimmerman's "ill will," prosecutor Richard Mantei said.

"It shows the context in which the defendant sought out his encounter with Trayvon Martin," he said.

In addition to Jeantel and the recordings, jurors heard from several other witnesses for the prosecution Wednesday, including two of Zimmerman’s neighbors.

Neighbor Jane Surdyka says she was in a second-floor bedroom of her townhome when she heard scuffling outside on the rainy night.

Surdyka says she then heard what she believes were a boy's cries for help.

"I truly believe the second yell for help was a yelp," said Surdyka, who later dabbed away tears as prosecutors played her 911 call. "It was excruciating. I really felt it was a boy's voice."

Surdyka told the court that before the shooting, she heard an aggressive voice and a softer voice exchanging words for several minutes.

"It was someone being very aggressive and angry at someone," she said.

During the struggle, she said, she saw a person in dark clothes on top of the other person. Martin was wearing a dark sweatshirt and Zimmerman wore red clothing. Surdyka said she saw the person who was on top get off of the other person after the shot was fired.

During cross-examination, West tried to show there was a lapse in what Surdyka saw. Defense attorneys contend Martin was on top of Zimmerman during the struggle, but after the neighborhood watch volunteer fired a shot, Zimmerman got on top of Martin.

West also challenged Surdyka about her belief that the cry for help was a boy's voice, saying she was making an assumption.

Another neighbor, Jeannee Manalo, testified after Surdyka that she believed Zimmerman was on top of Martin. Manalo also described hearing howling, but she couldn't tell who it was coming from.

Under cross-examination, defense attorney Mark O'Mara asked why she had never mentioned her belief that Zimmerman was on top in previous police interviews. He made her read back a transcript of an interview in which she described only seeing shadows.

Zimmerman has pleaded not guilty, claiming he shot the teen in self-defense. Zimmerman could face life in prison if convicted.

Fox News' Serafin Gomez and The Associated Press contributed to this report.