Several of the 12 jurors who found themselves unable to agree whether former nurse Mary Rose Robaczynski had murdered a comatose patient said their confusion over Maryland's legal definition of brain death led to the deadlock.

Baltimore prosecutors met yesterday with 11 of the jurors and came away uncertain whether any jury could understand the existing law.

Robaczynski was accused of murdering patient Harry Gessner by unhooking his respirator, but the defense contended that Gessner was legally dead hours before the disconnection.

A mistrial was declared late Tuesday when the jurors, after 19 hours of deliberation, deadlocked 10 to 2 in favor of acquittal, according to one jury member.

"Everybody agreed that what Mary did was wrong," Assistant State's Attorney Peter Semel said yesterday, after an hour-long talk with the jurors. "But they couldn't decide whether he [Gessner] was dead or alive."

"It was the first case I ever had to try," Semel said, "where I had to prove the victim was alive before he was dead."

To help the prosecutors decide whether to retry the case, Semel said, the jurors were asked to meet when they returned to jury duty on other cases yesterday. Eleven jurors agreed to the meeting, Semel said.

Semel said he and Assistant State's Attorney Howard Gersh will decide "probably next week" whether to retry the 24-year-old Robaczynski on this charge, or on any of three other charges of murdering patients by respirator disconnection.

After the mistrial was declared, jury foreman Beverly Skotarski told reporters, "We couldn't even decide whether he [Gessner] was dead."

Juror Teresa Severe agreed. "The main thing was the law they had defining whether the man was dead or alive," she said. "It was hard to make a decision."

That law is the 1972 Maryland statute that says, in part, that a patient may be declared legally dead when there is an absence of "spontaneous brain function." The defense hinged its case on those three words, maintaining that under that definition, the 48-year-old Gessner was "brain dead" before the disconnection.

Severe, a 53-year-old Baltimore housewife, said that each of her fellow jurors put his or her own interpretation on the word "spontaneous."

Some legal and medical experts now believe that the word "spontaneous" should be left out of future statutes defining brain death.

"Its' unnecessary, a mistake, because of the potential confusion," said University of Pennsylvania law professor Alexander Capron, who has worked as a consultant with a national lawyers group that it proposing enactment of a uniform brain death law by all the states.

Minneapolis brain specialist Ronald Cranford, who also worked on the proposal, said the law would define brain death as occurring when all functioning in every part of the brain ceases.

Though the Maryland statute was defended by several legislators and local doctors yesterday as clear, both prosecutors and defense attorneys in the Robaczynski case said it was "too vague."

Defense attorney Joseph F. Murphy Jr. said the law was enacted to help doctors in organ transplant cases, but if it is going to be applied in criminal cases "it could use some improvement."