VIRGINIA BEACH, Va. - Jonathan Shapiro says he hesitated last November to accept his friend and fellow Virginia defense attorney Peter D. Greenspun's offer to serve as co-counsel for sniper suspect John Allen Muhammad.

Shapiro knew that some people - even a few friends and relatives - would rebuke him for defending a man who, along with an alleged accomplice, is accused of killing at least 13 people across the country last year and plunging the Washington region into three weeks of panic.

Shapiro's 15-year-old daughter, Emma, set him straight, he says, by asking him, "Isn't this your job description, Dad?"

Today, Shapiro and Greenspun will begin the defense portion of Muhammad's death-penalty trial.

In a recent interview at the Virginia Beach courthouse that has been their home of sorts for a month, the two veteran lawyers talked about the frustrations of taking a high-profile case and some challenges they have encountered in defending a man accused of serial murder.

Muhammad faces two counts of capital murder in the death of Dean H. Meyers, 53, at a gas station near Manassas, Va., on Oct. 9, 2002. One count is under Virginia's untested anti-terrorism law. The other alleges he killed more than one person in three years. Prosecutors have presented evidence from several other killings they say are connected to Muhammad, 42, and co-defendant Lee Boyd Malvo, 18.

Both charges carry a possible death sentence, something the defense attorneys - both married fathers of three - say they vigorously oppose.

Shapiro's family vividly remembers the only time one of his clients was put to death. Wilbert Evans, convicted of murder in the killing of an Alexandria sheriff's deputy in 1981, was electrocuted Oct. 17, 1990. His defense attorney of eight years sat in the next room, near a telephone, waiting for a call from the governor that would never come.

"He really feels the responsibility he carries," says his eldest daughter, Meghan, 19 - an aspiring attorney.

She says that if Muhammad is convicted, she won't be surprised if her father cries during the sentencing phase of the case. Greenspun has spearheaded the guilt phase; Shapiro will oversee sentencing if Muhammad is convicted.

The two lawyers say the thought of Muhammad being sentenced to death never leaves their minds.

"There's great responsibility in knowing that the guy at the end of the table, they're trying to kill," Shapiro says. "You can never forget that.

Greenspun adds, "Particularly at 1 and 2 in the morning ... and 3 and 4."

Greenspun, 50, gained public attention when he represented sportscaster Marv Albert in 1997 on sodomy charges. Colleagues have called him one of the best criminal defenders in Virginia.

At 54, Shapiro is known as a dogged lawyer - he refused to give up a case even after a client knocked him out in the courtroom in October 2000.

Shapiro was representing Gregory D. Murphy, who had been charged in the stabbing death of an 8-year-old Alexandria boy. At the end of a routine hearing, Murphy unexpectedly turned on Shapiro and delivered a forceful punch to his jaw.

The lawyer was knocked unconscious and taken to the hospital by ambulance. Although Shapiro wanted to remain Murphy's attorney, a judge later reassigned the case.

Elliott S. Milstein, one of Shapiro's former law professors at American University, says that incident illustrated his commitment to his clients and to the judicial system as a whole.

"He's a warrior for justice," Milstein says of Shapiro, whose solo practice is based in Alexandria. "He's really one of the great ones."