A 20-year-old Northern California man suspected as being one half of the high-profile "Deceptive Duo" hacking team is scheduled to appear in court on Monday to face charges of breaking into government computers and defacing government Web sites.

Robert Lyttle, who allegedly teamed up with 22-year-old Benjamin Stark and hacked into computer systems run by the Department of Defense and the National Aeronautic and Space Administration (NASA), faces a maximum statutory penalty of 10 years if he is found guilty, authorities announced.

Earlier this year, Stark pleaded guilty to charges of hacking and defacement of U.S. government Web sites. He faces up to 30 months in jail after agreeing to a plea bargain with prosecutors.

According to the U.S. Attorney's Office, Lyttle gained unauthorized access to computer systems of the Defense Department's Logistic Information Service (DLIS) in Battle Creek, Mich. Once in, he stole files which were later used to deface a Web site belonging to the department's Office of Health Affairs (OHA).

He has also been charged with breaking into a NASA ARC computer located at Moffett Field, Calif., and obtained information from that computer for the purpose of defacing a Web site hosted on the computer.

The indictment alleges that Lyttle caused damages in excess of $70,000.

The U.S. Attorney's Computer Hacking and Intellectual Property (CHIP) Unit is overseeing the prosecution.

In April 2002, the "Deceptive Duo" group grabbed headlines for defacing U.S. government Web sites under the ruse of protecting the country from online terrorists by highlighting security flaws in critical systems.

Those attacks included the defacement of the U.S. Space and Naval Warfare Systems Command. Back then the team said the break-in was done to "ensure that the public is aware of the United States of America's lack of security."

In May 2002, the pair allegedly broke into the Web server of one of the U.S. Navy's databases and published a database of information including e-mail addresses and phone numbers of top Navy and White House brass.

A roster containing the classified and unclassified e-mail addresses -- as well as contact phone numbers of Navy admirals, vice admirals and even the attending physician to Congress were published on one of the defaced pages of a Navy supporting Web site.