A Prince George's District Court judge said yesterday at a preliminary hearing for a nurse charged with killing a patient that he found probable cause that a crime had been committed. He delayed further proceedings, giving police 30 days to gather more evidence against Jane Bolding, 27.

Judge Irving Fisher's decision came after nearly two hours of testimony from a police detective assigned to the case, who read statements police said Bolding wrote admitting that she ended the suffering of Elinor Dickerson. She died in September while under Bolding's care at Prince George's General Hospital.

The detective also revealed notes from a police officer that said Bolding told him she also had given lethal injections to another elderly patient. Bolding has been charged with murder in Dickerson's death, but not in the death of the other patient, whose name police said they still do not know.

The judge's finding means State's Attorney Arthur A. Marshall, who has said repeatedly that, despite Bolding's confession, police do not have sufficient evidence to prove that a murder was committed, has a month to find new evidence to amend the charges or get an indictment from the grand jury before Bolding's lawyer can ask that the charges be dropped. Even if they are dropped, Marshall said, they can be reinstated if police later come up with new evidence.

Police said Dickerson's body was exhumed yesterday and an autopsy begun at the State Medical Examiner's office in Baltimore. Marshall cautioned that it could take as long as 30 days for those results to become available.

In the meantime, he said, he is looking for a lawyer familiar with medicine to help him with the case and is also trying to get assistance from experts at Walter Reed Army Hospital and the Centers for Disease Control in Atlanta.

During the hearing, county police Detective Robert Edgar read a statement made to police by Bolding shortly before she was arrested March 20 and charged. Edgar read two similar statements about Dickerson's death that he said were written by Bolding and addressed to a member of Dickerson's family.

Only the second statement was signed by the nurse, police said. It read: "The night your mother died in the ICU intensive care unit she suffered a cardiac arrest toward the end of the evening. She never regained conciousness and following her heart attack, I gave her 20 mg [Edgar said he could not read the measurement clearly] KCl [a chemical notation for potassium choloride] IV [intravenously] to stop her heart. I felt that that was a kind way to end her suffering. I'm sorry for the pain it may have caused you."

Edgar also read from notes taken by Detective F.M. McQuillan who talked with Bolding extensively during the more than 30 hours she was held last month for questioning. During those conversations, according to Edgar's testimony, Bolding told police that last fall she gave potassium injections to Dickerson and to an elderly male patient whose name she could not remember. The police statement said Bolding gave the injection to the man "to keep him from suffering."

Edgar told the court that he began investigating the case because hospital officials believed there were an unusual number of deaths in the intensive care unit. Edgar said between January 1984 and last March, there were 105 cardiac arrests in the unit.

"One nurse, that being Jane Bolding, had 51 cardiac arrests in her care," he said. Those attacks occurred in 22 patients, 17 of whom died, police have said.

At one point, Bolding's attorney, Fred R. Joseph, asked Edgar why he had not brought a 12-page statement also written by Bolding at the police station in which she denied any involvement in Dickerson's death. The police officer replied that he did not know that document would be needed at the hearing.

Following the hearing, Joseph said, "Jane Bolding is going to deny everything in those statements" because it was taken after 24 hours of questioning and was dictated to her by police.