Patricia Stephens carried a pair of scissors in her purse last Friday night when she went to visit her critically ill father at Howard University Hospital. When the attending nurse left the room, Stephens snipped the tubes that fed oxygen and liguid food to her father, who lay in a coma suffering from cancer, pneumonia and heart disease.

Then, Patricia Stephens, 39, unplugged the machine that kept her father breathing and sat quietly by his bedside and awaited his final heartbeats. After his final breath, she stood and made the sign of the cross over his body.

Stephens later told D.C. police detectives that she decided to take her father's life because she could not bear to see him suffer any longer.

D.C. Medical Examiner Dr. James L. Luke said that the death of Jeremiah Stephens, 65, was a case of euthanasia and that, to his knowledge, it was the first such case in the District of Columbia.

Details of Stephens' death have been recounted by various sources familiar with the case, which was classified by Luke as a homicide. Three days after the death, the U.S. Attorney's office presented evidence to a D.C. Superior Court grand jury. But the grand jury declined to bring any charges against Patricia Stephens.

It was learned that the grand jury's decision not to return an indictment in the case reflected the panel's sympathetic view toward Stephens' action.

Yesterday, Patricia Stephens, a British citizen who is a sociologist in London, attended her father's funeral with her family in their home town of Mt. Lambert, Trinidad, and could not be reached for comment.

Luke said his autopsy of Stephens showed that Stephens suffered cancer of the esophagus, which almost completely blocked his throat. Because Stephens could receive no solid foods, his 5-foot, 10-inch frame became extremely emaciated, Luke said.

According to Luke, Stephens also had suffered numerous heart attacks since he was admitted to Howard University Hospital on April 11.Stephens had gone into a coma following the first heart attack about 10 days before his death, Luke said.

"There is no question that the man was terminally ill," Luke said. "He would have died within hours or days of when this incident happened. . ."

According to sources close to the case, Stephens, a retired civil servant, came to the United States form Trinidad with his wife, Edith, last December to visit two daughters who live in the Washington area.

Shortly after his arrival here, Stephens was hospitalized at the Washington Adventist Hospital in Takoma Park for radiation treatment of extensive cancer of the throat, sources said.

Patricia Stephens arrived in Washington earlier this year when her father's health grew worse. In a diary that police conficated from Patricia Stephens as evidence, she expressed her desire to end her father's suffering, according to sources.

Last Friday, Patricia Stephens arrived at Howard University Hospital about 7:30 p.m., when a registered nurse was changing the linen on her father's bed, the sources said.

During a five-minute period when the nurse was gone from the room, Stephens took scissors she brought to the hospital in her purse and cut all the tubes that led to her father's lifesupport system, sources recounted. Then she unplugged his respirator from an electrical wall outlet.

When the registered nurse, Natividad O. Amaya, returned to the room, Stephens was making the sign of the cross over her father's body, sources said.

According to a D.C. Police report, Jeremiah Stephens was pronounced dead at 8:20 p.m. by Dr. Eileen M. Cummings of the Howard University Hospital staff.

LaRue Cook, the assistant hospital administrator on duty at the time, said yesterday that shortly after her father was pronounced dead, Patricia Stephens agreed to write a statement - at the hospital's request - in which she described what she did and why she did it.

"Without hesitating or showing any great concern," Cook said, "she sat down and made out statement in longhand describing what happened."

Another source said Stephens wrote two pages of longhand in which she expressed her strong desire to see her father "die in peace." The hospital had asked Stephens to write the statement to relieve the hospital of liability for Stephens' death, Cook said.

Shortly after hospital officials learned of Stephens' death, they contacted 3rd District police, who immediately turned the case over to homicide detectives for investigation.

According to a police spokesman, the U.S. Attorney's office agreed to present evidence to the grand jury on Monday and told police there was no need to arrest Patricia Stephens.

The U.S. Attorney's office would not comment on the case yesterday.