On Jan. 13, 1976, Gladys Hinckley Werlich, 85, a vibrant, independent woman of a gracious era long past in Washington was mugged by four youths as she walked along Corcoran Street NW. A blow from behind threw her to the ground and cracked her skull.

For five days, she lay in the intensive-care unit at George Washington University Hospital, semiconscious, unable to speak, her brain swollen and damaged. As part of her treatment, she was placed on a respirator.

On the sixth day, Mrs. Werlich's neurosurgeon, after consulting with her son and other doctors, turned the respirator off.

Within 20 minutes, Gladys Werlich was dead.

Who caused Mrs. Werlich's death? The youths whose attack resulted in her injury? Or the neurosurgeon who discontinued her treatment?

Those questions, with all the moral and ethical complexities that come with a medical decision to terminate life, have been brought to the D.C. Court of Appeals. There, the death of Mrs. Werlich has turned into a troubling, sensitive legal dispute.

The city's Public Defender Service, in behalf of one of the assailants convicted of Mrs. Werlich's murder, contends that the jury in the case should have gotten a chance to consider those questions, and asks that its client, Leroy Parker, be granted new trial.

The Public Defender Service argues that the neurosurgeon did not follow accepted medical practice when he decided to disconnect the respirator, but rather made a value judgment about the quality of Werlich's life as a result of her injury.

The public defender contends the doctor's action interrupted the chain of circumstances that would have linked Parker to Werlich's death. As a result, the service argues, Parker cannot be held liable for her murder.

Similar arguments have been raised in the appellate court for a juvenile also found guilty of Werlich's murder.

Chief Judge Theodore R. Newman Jr. and Associate Judge Frank Q. Nebeker and John W. Kern III heard oral arguments in the case involving the juvenile in May 1977, but postponed their decision until the Parker case is heard. That case is scheduled for oral arguments Thursday.

The U.S. attorney's office, in response to Parker's act was a reasonable and compassionate response toward an aged patient who had no chance of resuming the life she once enjoyed so much.

In its brief to the appeals court, the government notes that Dr. Michael W. Dennis, the neurosurgeon who treated Werlich, had concluded that she suffered "irreversible brain damage" during the attack on Corcoran Street, so much so that she would not have survived even if heroic measures - like the respirator - had been continued.

Parker should be held accountable for Werlich's murder, the government asserts, because the fact that the neurosurgeon found himself faced with the decision about the respirator was a direct consequence of the acts of Leroy Parker and the three other youths.

"It's a nicety argument," John Lewis Smith III, general counsel to the Medical Society of the District of Columbia, said when asked to comment to the public defender's contention.

"The law is inclined to say that you are responsible" for the consequences of your act, Smith said.

A decision to terminate life-support treatment "is a lot bigger problem when you have a bunch of clean hands. Here (with the injury initiated by a crime) you have dirty hands," Smith said.

"The idea that a defendant in a homicide case could be shielded from responsibility for the death of a victim by the intentional termination of life-support systems is not new," said the Public Defender Service, in a lengthy brief written by attorney Richard A. Rosen.

In criminal cases that have come before the courts nationwide, the public defender argues, doctors have concluded that their patients had suffered "brain death" before life-support machines were taken away.

The most widely accepted definition of brain death was set out by a committee from the Harvard Medical School in a 1963 article in the Journal of the American Medical Association. The criteria proopsed by the committee were that the patient be in an irreversible coma, that there be no spontaneous breathing or movements, in reflexes and no barin waves. If these criteria are met within 24 hours of initial tests, the patient will be declared dead and life-support treatment terminated, the committee said.

In case where there has been a finding of "brain death," the courts have held that a doctor's act in terminating life-support treatment will not shield a defendant from liability for homicide, the public defender said.

Werlich was not found to have suffered "brain death," the public defender contends. She was alive.

What she was, Dr. Dennis said during Parker's trial, and what she was doomed to be as a result of her injury, was "a patient who could not talk, a patient who could not walk, a patient who could not think, could not see, could not appreciate anything in the world."

During Parker's trial in February 1977 in D. C. Superior Court, Judge Nicholas S. Nunzio denied requests from Parker's defense attorney that the jury be instructed on the defense theory of the case - that Dennis' action caused Werlich's death. If the jury had considered - and then agreed - with the theory, it could have found Parker guilty of an offense less serious than homicide, such as assault or attempted robbery, the public defender argued on appeal.

Nunzio also refused to instruct the jury on what is known as the "year-and-a-day rule," a common-law principle that says death must follow within a year and a day after an injury if the assailant to be charged with murder.

The judge ruled that the defense failed to present enough evidence during the trial to warrant either instruction.

Parker, then 19 years old, was found guilty of second-degree murder and sentenced to 6 to 18 years in prison.The same jury found a second youth, then 17 years old, guilty of attempted robbery. Earlier, another 17-year-old pleaded guilty to murder and was sentenced to serve a maximum of six years in jail under the terms of the federal Youth Corrections Act. The fourth assailant, then 13 years old, was found guilty of murder in the city's juvenile court.

At Parker's trial, Dennis testified that he did not think Werlich would have survived even if she had been kept on the respirator, the government asserts.

If she lived, Dennis testified, "the best she could have hoped for would be a life in coma."

What the public defender argued however, is that Dennis, along with Werlich's son Robert, "reached the conclusion that (Mrs. Werlich's) life was not worth living and that she would eventually die without regaining consciousness."

In a recent interview, Dennis agreed that there was no finding of brain death in the Werlich case. The question with his patient - the basis of his decision - was "what to treat, when to treat and how to treat.

"When brain death is there, there is enough precedent so there is no problem," Dennis said. "Where the controversy exists is not in brain death but how much treatment to render an incurable patient."

On the sixth day of Werlich's treatment, Dennis had to decide whether to take the surgical procedures necessary to maintain his patient on a respirator for a long period.

Treatment with the respirator was not improving his patient's condition, Dennis contends. It was only prolonging her hopeless condition, and removing the respirator was only the cessation of useless treatment, he said.

In its brief, written by Assistant U.S. Attorney William J. Cassidy Jr., the government refers to the position of the American Medical Association, which states that the decision to stop extraordinary means to prolong life is one to be left to the doctor and his there is irrefutable evidence that biological death is imminent.

Doctors in Washington who are faced with these kinds of decisions will find no guidance in D.C. law. There is only a pres release put out by the D.C. Medical Society in 1976, which says that when artificial means are used to support a patient the patient will be "deemed dead" if, in the physician's opinion and based on ordinary standards of medical practice, there has been "an irreversible cessation of spontaneous brain function."

The government, in response to Parker's appeal, contends that Dennis' action, based on his assessment of Werlich's chance of recovery, was well within the bounds of accepted medical practice.

The public defender does not dispute the contention that there are instances in which a doctor, applying standards or other criteria, can terminate treatment with life-support systems.

But, the public defender does disagree with any contention "that it is both reasonable and proper for a doctor to make an ad hoc decision to end another's life simply because he and the patient's family feel that life no longer had any value."

Legal observers feel that the Werlich case and others like it raise broad questions about what society hopes to accomplish through the criminal law.

". . . are these people any less dangerous by the happenstance that she didn't die at the scene?" asked Joseph Goldstein, a professor of criminal law at Yale Law School.

"Should these kids be protected by doctors who use extraordinary efforts to save the life of a victim?" Goldstein asked.

John A. Robertson, a professor of criminal law and medical ethics at the University of Wisconsin's Schools of Law and Medicine, theorized that if Werlich would have died very shortly after she was attacked, and if the doctor's act in turning off the respirator only hastened her death, then the defendants would not be shielded from liability for her murder. That is the government's argument.

However, Robertson said, if she would have lived, even in a very damaged state, the doctor's act would break the link needed under the law to charge Leroy Parker and the juvenile defendant with murder.

Both sides in the Parker case contend that the 1976 New Jersey Supreme Court decision in the tragic case of Karen Ann Quinlin supports their arguments in the Werlich case.

The New Jersey court ruled that Quinlan, then 2 years old and in a coma for 350 days, could be removed from life - support systems if her father, who was named her legal guardian, her attending physician, and a hospital ethics committee agreed that she would not emerge from her vegetative state. Quinlan, now free of any life - support system, remain in a coma today.

Quinlan, like Werlich, had not suffered "brain death." But, the public defender in Washington contends that before the New Jersey court would approve withdrawal of the life-support system, it required the concurrence of a party beyond her family and doctor - the ethics committee.

As for the Quinlan case, the government says in its brief to the Court of appeals, the New Jersey court noted that "medical decisions to terminate artifical life - support systems in cases in which the patient is not braindead are humane responses to the irreversibly injured person."

"We submit that the decisions made with respect to Mrs. Werlich were similary humane and reasonable responses to her condition," the government said.

There is a final, said twist to the Werlich case that was not raised in the trial court and has not been brought to the D.C. Court of Appeals.

According to Dennis and a relative, several years before her death, Werlich had signed what is known as a "living will." It was a legal statement to be used in case she were ever unable to express her own wishes.

In it, she said, she did not want to be kept alive by artificial means.