Jury selection for George Zimmerman's second-degree murder trial begins today, and in yet another controversial move seeking to prove their client's justification for self-defense, his lawyers have released a video that' allegedly one of the only recordings of Trayvon Martin's voice — and they claim it proves Martin wasn't, in fact, screaming for help in a 911 call. The video in question is actually a would-be piece of evidence that, like so much of the character assassination that has leaked ahead of the trial, Zimmerman's attorneys have already had to apologize for; after drumming up support for the defendant by claiming the footage showed Martin beating up a homeless man, Mark O'Mara and Co. were forced to admit that Martin just filmed two homeless men fighting over a bicycle. But now the lawyers insist the video — or at least its audio — raises new questions. So here it is:

You can hear multiple voices there — it's difficult to tell which one is allegedly Martin's, what with everyone laughing. But the defense claims this is the only existing recording of Martin's voice — an important caveat, since that would mean a 911 call on the night he was shot last February did not include his voice. Indeed, the attorneys say the voice in the video above doesn't match the voice on a 911 call that includes a man screaming Help meNBC News reports. Importantly, the court still has to determine if the 911 call is admissible — unlike Martin's history of "violence" and marijuana use, Judge Debra Nelson hasn't thrown out that piece of evidence — but if the prosecution's experts are allowed to testify, that could still break Zimmerman's claim of self-defense, around which the trial will revolve. "Alan Reich, a voice analysis expert who testified Friday, believes that the screams recorded were not Zimmerman, but more likely came from Martin," CNN reports from last week's pre-trial hearing on the admissibility of the evidence. "Ted Owens, a forensic audio engineer, testified Friday that his analysis of the 911 call indicated that the person screaming was not Zimmerman."

That the video shows people laughing at two homeless people fighting, of course, is something of another character attack on Martin, which Zimmerman's lawyers aren't exactly being coy about.  "Asked whether it could be used in a way damaging to Martin's image, Shawn Vincent, a spokesman for the defense, said: 'The answer is we hope it doesn’'t.'" NBC News reported. Calling Martin's character into question has been one of the main pre-trial strategies from the defense, at least out in the open: They've leaked stories to the press about Martin's emails and text messages, which allegedly show a "violent side." They've also tried to bring Martin's past, from his marijuana use to school suspensions, into the spotlight; last month the judge ruled that the two sides cannot use this evidence.  The Martin family has called these leaks "a desperate and pathetic attempt by the defense to pollute and sway the jury pool." They probably feel the same way about this video now that it, too, is out in the open. 

Jury selection starts this morning and is expected to last for a while. Judge Nelson will hear the arguments about the 911 call at a later date. You can watch today's hearings streaming live right here(Update: Judge Nelson has denied Zimmerman's motion to delay.)