George Zimmerman maintains that the cries for help in the 911 phone-call were his

George Zimmerman’s defense team have maintained their client’s innocence, saying Zimmerman was badly beaten and acted in self-defense. They have challenged key pieces of the prosecution’s case.

One of the most potentially essential pieces of evidence deals with the screaming in the 911 phone call. Determining who was the person screaming for help may be crucial in concluding who was the aggressor.

The murdered teenagers father, Tracy Martin, has said he is “positive” the pleading voice is that of Trayvon. However, Zimmerman’s lawyers request a second interview with Sanford police investigator William Erwin, who overheard the teen’s father say the screaming voice was not that of his son and the defense lawyers have filed a motion to that effect.

Zimmerman’s defense team have also asked that the prosecution “disclose all witnesses known to the state who claim to be familiar with Trayvon Martin’s or George Zimmerman’s voice that have heard” the 911 call. Additionally, the defense team has filed a motion which asks the court to force Benjamin Crump, the Martin family’s attorney, to turn over the original recording and recording device that he used to first interview the late teenager’s girlfriend.

Zimmerman has also asked that he be allowed to remove his GPS monitor and leave Seminole County without the court’s permission. The next court hearing is December 11th.