After an initial flurry of publicity, the police investigation of a former Prince George's General Hospital nurse charged with killing a patient has shifted into a quieter, painstaking probe of hospital records as detectives seek to bolster a case that even the state's attorney has acknowledged is weak.

According to law enforcement sources and lawyers involved in the case, authorities may exhume the body of Elinor Dickerson, the 70-year-old woman who police allege was given a lethal dose of potassium at the hospital in September.

Hospital officials originally said that Dickerson died of massive heart failure, but late last month police charged Jane Bolding, 27, with first-degree murder in Dickerson's death. Police say that Bolding admitted injecting Dickerson, a patient in the hospital's intensive care unit, with potassium to end her suffering.

Bolding faces a preliminary hearing April 18, and State's Attorney Arthur Marshall has said that he needs more evidence in the case before he will prosecute.

So police are reviewing the histories of numerous patients treated by Bolding, who worked in the hospital's intensive care unit, according to hospital and law enforcement sources. Although Marshall and police officials acknowledge that a high concentration of potassium would be very difficult to detect in Dickerson's body now, Marshall has encouraged police to conduct an autopsy.

A hospital investigation into Bolding's activities began a month ago, when a 16-year-old accident victim in the intensive care unit had three unexplained heart attacks while under Bolding's care. The nurse has not been charged in that case. The hospital fired Bolding following her arrest.

The mother of that 16-year-old, who asked that the family's name not be used, said her son was moved from intensive care to a regular room last week and is now able to talk. She said that the boy suffered a broken jaw and lost an ear as a result of a hit-and-run accident about two months ago, and he is still battling serious infections.

She said doctors told her that her son's heart probably was permanently damaged by the heart failures, and said that she is planning to sue the hospital for negligence. She has been counseled by her attorney not to talk about her earlier contacts with Bolding at the hospital.

Marvin Ellin, the Baltimore attorney representing Dickerson's two daughters, said he has informed Marshall's office that the family is encouraging, and is willing to pay for, the exhumation of Dickerson's body, which is buried in Fredericksburg, Va.

"First they're told their mother died of natural causes," Ellin said. "The next thing they hear is that some nurse may have murdered her. They want an answer to the question, 'How did Elinor Dickerson die?' "

Assistant State's Attorney Norman Kiger said he has spoken with Ellin about arranging to exhume the body, and police are checking with Virginia authorities to see what procedures must be followed.

"I'm thinking that by midweek something will be happening," Kiger said Thursday.

Ellin said the family is considering a suit against the hospital if an autopsy shows that Dickerson was improperly cared for.

Dickerson died at Prince George's General several days after she was put in the intensive care unit following emergency surgery for intestinal bleeding.

Law enforcement and hospital sources said last week that police are pursuing their case by interviewing hospital employes and poring over medical records. Sources said the police are considering calling in federal medical experts to help.