George Zimmerman 'not guilty' plea at arraignment for Trayon Martin killing

New evidence has been released in the shooting death of Trayvon Martin, including a medical examiner's report on the victim and photographs taken of assailant George Zimmerman shortly after their fatal confrontation.
How strong is case against Zimmerman?
Trayvon Martin, George Zimmerman

(CBS) SANFORD, Fla. - A written plea of not guilty was entered today on behalf George Zimmerman, the central Florida neighborhood watch leader who's charged with murder in the shooting death of 17-year-old Trayvon Martin.

Pictures: George Zimmerman faces murder charges

Zimmerman did not attend Tuesday's formal arraignment in Seminole County, where the juget set a pre-trial hearing date of Aug. 8, CBS affiliate WKMG reported.

Zimmerman's attorney, Mark O'Mara, filed the not guilty plea on behalf of his 28-year-old client and waived Zimmerman's appearance. O'Mara also waived Zimmerman's right to a speedy trial in filing for a continuance, citing the need for more time to prepare the defense case.

In another development, O'Mara said that of the $200,000 raised by Zimmerman's now-defunct website, just under $50,000 is being used for his security and setting up his living arrangements in hiding. The other $150,000 has been turned over to an independent administrator to manage.

Zimmerman is charged with second-degree murder in Martin's Feb. 26 shooting death in Sanford.

Martin's family and supporters claim the black teen was a victim of racial profiling.

Zimmerman has claimed Martin attacked him and that he fired in self-defense.

Complete coverage of the George Zimmerman-Trayvon Martin case on Crimesider