George Zimmerman trial: Neighbor of accused Trayvon Martin killer says she heard "yelps" and cries for help

George Zimmerman, left, arrives in Seminole circuit court, with his wife Shellie, on the 11th day of his trial, in Sanford, Fla., Monday, June 24, 2013. Zimmerman is accused in the fatal shooting of Trayvon Martin. Zimmerman has been charged with second-degree murder for the 2012 shooting death of Trayvon Martin. (AP Photo/Orlando Sentinel, Joe Burbank, Pool)
Witness Jennifer Lauer testifies during George Zimmerman's trial in Seminole circuit court in Sanford, Fla., Thursday, June 27, 2013.
AP Photo/Orlando Sentinel, Jacob Langston, Pool

(CBS/AP) SANFORD, Fla. A neighbor of George Zimmerman who called 911 the night he fatally shot unarmed teen Trayvon Martin said she heard "yelps" and screams for help outside her home.

PICTURES: George Zimmerman on trial in death of Fla. teen

VIDEO: Zimmerman trial: Prosecutor opens with profanity

Jenna Lauer took the stand Thursday afternoon in the fourth day of testimony in Zimmerman's second-degree murder trial. Zimmerman claims he shot the teen in self-defense.

Lauer testified she heard an exchange that was presumably between two people. She then heard a scuffling, "like sneakers on pavement and grass."

"It kinda sounded like wrestling," Lauer said. "At one point I felt like they were going to come through the screen.'"

Jurors heard Lauer's 911 call, during which screams can be heard in the background and the fatal shot was fired.

"It just sounded like they were desperate," Lauer said. "Whoever it was really needed help or they wanted help."

Lauer testified she didn't know who was screaming. Who was screaming has been a key point of contention in the case.

"How could you not listen to that phone call and be emotionally attached to it? It's not only the screaming of someone fighting for their life, it also evidences the death of a 17 year old," said defense attorney Mark O'Mara, speaking in a press conference following proceedings Thursday evening. "It's a very emotion-packed piece of evidence to listen to. Unfortunately it's critical for [the jury] to listen to it."

READ: Trayvon Martin Shooting: A timeline of events

Attorneys continued questioning Lauer, who, without the jury in the courtroom, said she knew George Zimmerman. Defense attorney Mark O'Mara asked whether Zimmerman's behavior or his involvement with the community's neighborhood watch ever concerned her.

"Did he ever seem angry to you at all?," O'Mara asked.

"No," Lauer replied.

Prosecutors asked Lauer whether she knew about a restraining order and an arrest in Zimmerman's past. Lauer said she did know about the incidents, but only after watching media reports.

Another former neighbor, Selma Mora, testified that she heard a crying sound outside her home. She then heard a "dry" sound "which I have described as the thump of a child falling," Mora said in Spanish, through an interpreter.

When she went outside, she said, she two people on the ground. One was on top, she said, in the position of a "rider."

Before Lauer and Mora took the stand Thursday, Trayvon Martin's friend who was on the phone with him moments before his death wrapped up her extended testimony.

Defense attorney Don West zeroed in on slight differences among three different accounts of what Rachel Jeantel said happened before Martin's killing, in an apparent effort to discredit her. Jeantel, 19, has described what she heard over the phone in a deposition; in a letter to Martin's mother; and an interview with the Martin family attorney. West said in some accounts, she said race was an issue, but not in others.

Jeantel testified Wednesday that her friend's last words were "Get off! Get off!" before Martin's phone went silent. But on Thursday, under cross-examination, she conceded that she hadn't mentioned that in her account of what happened to Martin's mother, Sybrina Fulton. She had left out some details to spare Fulton's feelings, and also because neither Fulton nor the Martin family attorney asked her directly about them, Jeantel said.

In another apparent disparity pointed about by West, after Martin asks why he is being followed, Zimmerman responds, "What are you doing around here?" in one account by Jeantel. In another account, according to West, she says Zimmerman said, "What are you talking about?"

West also questioned Jeantel as to how she knew from the phone call that Martin wasn't the aggressor in the confrontation.