When he was in Iraq, Lance Cpl. Stephen B. Tatum wore what were called "the thickest glasses in Kilo Company."

The 26-year-old native of the small town of Edmond, Okla., is represented by Houston-based defense attorney Jack Zimmerman, a lawyer known well in legal circles who earned two Bronze Stars and has a Purple Heart from his service in the Marine Corps.

On Thursday, Tatum was charged with two counts of unpremeditated murder and one count of negligent homicide related to the deaths of four Iraqis in Haditha and one count of assault. If convicted of the most serious of the charges, he would face the possibility of life in prison, a dishonorable discharge and forfeiture of all pay and allowances.

Tatum's family has refused requests for interviews and Zimmerman has instructed the Marine not to talk to reporters.

Zimmerman, a retired colonel who once led a Houston-based reserve infantry battalion, has said repeatedly that Tatum and his squad mates did nothing wrong in Haditha.

"Lance Cpl. Tatum was doing the job he was trained to do, the way he was trained to do it," Zimmerman told the North County Times earlier this year. "And unless someone has had shots fired (at them) in anger, you should not jump to conclusions until they know all the facts," he said.

Zimmerman said he believes there was "no criminal intent" involved in the shootings.

"I believe that if the military justice system is allowed to function the way it is designed, Lance Cpl. Tatum is going to be cleared of any criminal wrongdoing."

Tatum, who is single, joined the Marines in October 2003 and is a veteran of fierce battles in the Iraqi city of Fallujah in 2004, the attorney said. He was two months into his second assignment in Iraq when the Haditha killings took place.

A former prosecutor and military judge who spent 20 years in the Marines on active duty and the reserves, Zimmerman said he cut his usual fees in half to take Tatum's case.

A second Houston attorney, Christopher Odell, is acting as trustee for fundraising efforts for Tatum's defense.

Odell said in September that $15,000 in legal fees had already been incurred, adding that the cost to defend Tatum could "easily exceed the six-figure mark."