Screams in 911 calls aren't Zimmerman

Josh Voorhees, Abby Ohlheiser, and Daniel Politi have an article in Slate about the shooting in Florida:

One of the key questions that remains open about the Trayvon Martin shooting is who was the person who could be heard crying for help during a 911 call moments before a shot can be heard. Martin’s family insists he was the one begging for help, while the family of George Zimmerman, who shot Martin, disagrees. The Orlando Sentinel asked two forensic experts to analyze the evidence and, with a surprising amount of confidence, both say it’s clear Zimmerman was not the one screaming.
One expert used voice identification software to compare Zimmerman’s initial 911 call with the screams and concludes “with reasonable scientific certainty” that it wasn’t his voice on the tape. Another expert, who doesn’t use the software, but rather relies on human analysis, says he believes “without a doubt” that Martin was the one screaming, reports the Orlando Sentinel.
For those who have found it difficult to keep track of the facts in the case that has exploded into the biggest news story in the country, the Miami Herald publishes an in-depth piece, detailing everything that is known, and the questions that remain, about the shooting. The story puts in evidence how witnesses who claim to have seen at least part of the altercation between Zimmerman and Martin often gave starkly contradictory statements.
Confusion over the case seems natural, considering that different media outlets have been emphasizing very different accounts of what happened on that fateful Sunday evening, notes the Los Angeles Times’ James Rainey.
Friday, March 30: In a sit-down interview with CNN's Piers Morgan, Robert Zimmerman Jr. said that his brother George would be dead if he had "not acted decisively and instantaneously in that moment when he was being disarmed" by Trayvon Martin.
Robert Zimmerman's comments came the same day that ABC News broadcast a surveillance video showing his brother arriving at the police headquarters shortly after he shot and killed the Florida teen. While George Zimmerman has claimed he did so in self-defense and only after he was beaten by Martin, the video does not appear to show any blood or bruises on Zimmerman, leaving some doubting his version of events.
Robert Zimmerman, however, suggested that his brother's injuries— which his supporters say included a broken nose and cuts to the back of the head— were in fact real, merely unable to be seen on the video, possibly because he had received medical attention at the scene.
Meanwhile, the funeral director who prepared Martin's body for burial said he saw no signs that the seventeen-year-old had been in a physical confrontation with Zimmerman as the neighborhood watch volunteer has claimed. "We could see no physical signs like there had been a scuffle or there had been a fight," Richard Kurtz told CBS News. "The hands— I didn't see any bruised knuckles or what have you. And that is something we would have covered up if it would have been there."
Thursday, March 29: ABC News has yet another piece of evidence to submit in the public opinion wars over whether George Zimmerman should be arrested for shooting and killing seventeen-year-old Trayvon Martin in what he says was self defense.
The network has a surveillance video of Zimmerman arriving at police headquarters shortly after the incident that appears to contradict his— and the police report's— version of events that led to Martin's death. Zimmerman says he was punched in the nose, knocked over, and that his head was slammed into the ground by Martin. But, in the video, Zimmerman has no visible blood or bruises.
The Sanford police report has backed up parts of Zimmerman's version of events, noting blood on the back of his head and nose after the confrontation, and adding that he received medical attention at the scene before being taken to the station.
But Martin's family says that the video proves that Martin was not killed in self defense, according to CNN. Sybrina Fulton, Martin's mother, called the new video the "icing on the cake," for evidence that Zimmerman should be arrested.
Tuesday, March 27 2:50 p.m.: ABC News has the latest scoop: The lead homicide investigator in the shooting of Trayvon Martin originally recommended that police charge George Zimmerman with manslaughter the night of the shooting.
The network, citing multiple sources, reports that Investigator Chris Serino was instructed, however, not to press charges against Zimmerman because the Florida state attorney's office had determined that there wasn't enough evidence to lead to a conviction.
ABC News also reports that Zimmerman was brought to the police station for questioning "for a few hours" on the night of the shooting, despite his request for medical attention first, and that Serino filed an affidavit on the night that Martin was killed that stated he was unconvinced by Zimmerman's version of events.
The state attorney's office declined to comment when asked about the affidavit by ABC.
Tuesday, March 27 at 12:37 p.m.: As federal investigators continue to look into the Trayvon Martin case, the media's attention appears to have shifted somewhat to the seventeen-year-old's apparent troubled past.
The Miami Herald reports that Martin was suspended from school three times over the past year, including once last year for spraying graffiti on school grounds. According to the paper, in the aftermath of that incident, a school police officer who confronted Martin the following day found a dozen items of women's jewelry and a screwdriver in his backpack. The officer described the screwdriver as a "burglary tool" in his police report, although Martin was never charged or specifically disciplined for that incident.
Here's more on the incident from the Herald:

Trayvon’s backpack contained twelve pieces of jewelry, in addition to a watch and a large flathead screwdriver, according to the report, which described silver wedding bands and earrings with diamonds.
Trayvon was asked if the jewelry belonged to his family or a girlfriend. “Martin replied, it’s not mine. A friend gave it to me,” he responded, according to the report. Trayvon declined to name the friend.

Martin had never been arrested, according to police and his family. However, he was also suspended from school after being caught with an empty plastic bag with traces of marijuana in it, and once for tardiness and truancy.
A family lawyer, Benjamin Crump, confirmed the suspensions to ABC News, but called the information "irrelevant" to the case. He likewise cast doubts on the Sanford police leak confirming much of Zimmerman's account of the lead-up to the shooting, calling it a "conspiracy" to further cloud the case.
Tuesday, March 27: As George Zimmerman and Sanford police defend themselves in the face of growing outrage over Trayvon Martin's death, the seventeen-year-old's parents are visiting Capitol Hill to attend a racial profiling hearing organized by Democrats on the House Judiciary Committee.
Zimmerman, a 28-year-old neighborhood watch volunteer, shot and killed Martin last month, claiming self-defense. As details of the case spread over social networks and national media outlets, many advocates have increased calls for Zimmerman's arrest and have claimed that his actions, along with the decision by the Sanford police not to arrest him, were racially motivated.
The Justice Department and a Florida grand jury are examining the evidence in the case.
After President Obama offered his first public comments on the case— "If I had a son he would look like Trayvon," he said— new information that appears to support Zimmerman's version of the incident began to emerge this week.
Zimmerman reportedly told police that he was approached from behind by Martin, and then was attacked after a brief exchange of words. Sanford police say they have witness accounts that corroborate much of this version of the story, but few specifics have so far emerged, including when Zimmerman pulled his gun. Further clouding the issue is the fact that the Sanford police department itself is under scrutiny for its decision not to arrest Zimmerman, raising questions about the timing and the veracity of the leaked info.
Meanwhile, GOP hopefuls Newt Gingrich and Rick Santorum have spoken out against Obama's remarks on the case, which they say are dividing Americans by bring racism into the discussion. Gingrich said Obama's words were "disgraceful" and "appalling." And, as Politico points out, Santorum has been saving his harshest remarks about the race discussion surrounding the Martin case for the conservative airwaves. He told Laura Ingraham, referring to Obama's remarks about Martin, that "to introduce this type of rhetoric that is clearly meant to bring up these very sensitive issues I just think is out of line for this president."
An earlier version of this post was unclear on where Zimmerman received medical attention. He was briefly treated at the scene before being taken to the local police station.

Rico says no one has yet published any data from the autopsy; if the story is as Zimmerman told it (which Rico highly doubts), there should be powder burns on the kids' clothing...