Updated

A soldier accused of trying to pass military information to Al Qaeda (search) was shown in a videotape at his court martial Tuesday detailing weaknesses of the Army's primary battle tank to undercover federal agents.

The audio was muted on segments of the tape, and a gray blur obstructed Spc. Ryan G. Anderson's (search) mouth to block what he was saying at times. Prosecutors say Anderson believed the men were members of the Al Qaeda terrorist network.

"I have no belief in what the American Army asked me to do," Anderson said on the video. "They sent me to die."

The second day of Anderson's court-martial was closed to the public for long stretches so the judge and jury of commissioned officers could hear sensitive or classified testimony.

On the tape, Anderson offers sketches and information about weaknesses in the M1A1 Abrams (search) and identifies the crew compartment, main gun and other components he described as vulnerable.

Prosecutors attempted to show that information on the tape could have endangered soldiers' lives.

Al Qaeda expert Christopher Wallace testified that the details Anderson shared would have been helpful to terrorists, but acknowledged during cross-examination that the information also could be found on the Internet.

An expert on the ability of soldiers to survive in military vehicles testified for about 15 minutes in open court about his background. Then, Judge Debra Boudreau asked members of the public to leave for 45 minutes of further testimony.

She again closed the courtroom after Abrams tank expert John Rowe confirmed that a tank's hull could be weakened by damaging panels on either side of the tank, as Anderson said on the videotape. The court was closed for more than an hour of classified testimony by Rowe.

Ryan, a 27-year-old Muslim convert, could get life in prison without parole if convicted of five charges of trying to provide the terrorist network with information about U.S. troop strength and tactics, and methods for killing American soldiers.

Defense lawyer Joseph Morse said in opening arguments that the National Guardsman often embellished the truth or lied to impress people, but is not a threat to national security.