After 12 weeks of testimony and more than 90 witnesses on both sides, testimony in the case of The People of the State of New York V. Jean Harris ended today.

The prosecution brought out its final rebuttal witness, a Long Island skin pathologist who testified that tissue found in the slain Dr. Herman Tarnower's chest had come from the palm of the hand. The defense brought out its only rebuttal witness, a skin pathologist who testified just the opposite. ("My diagnosis is unequivocal!" that gentlement said.)

And then, at 5:30 p.m. on the dot, Judge Russell R. Legget turned to defense lawyer Joel Aurnou.

"Both sides rest?" he asked.

"Absolutely," said Aurnou.

Harris, the former headmistress of the Madeira School in McLean, Va., has been in court since October, charged with second-degree murder in the shooting death of Tarnower, her lover for 14 years, in the bedroom of his Westchester, N.Y. home.

The prosecution -- noting that Tarnower had been seeing another woman, his assistant, Lynne Tryforos, and that he had been shot four times -- says Harris shot her lover intentionally ina jealous rage. They also content Harris shot Tarnower as he raised his hand to defend himself and that the bullet that tore through his hand ultimatgely came to rest in his chest.

The defense claims Harris made the five-hour drive to Tarnower's home with a .32-caliber revolver intending to kill herself and that the doctor suffered the wound in his hand as he wrested the gun away from Harris' head. The doctor's other wounds, they claim, were suffered in a struggle with Harris for the gun.

Whether Tarnower was shot as he raised his hand in defense has been central to this case, and for that reason both sides have brought in pathologists to debate the issue of whether skin found in the doctor's chest came from his hand.

Tryforos, the woman the public and press had hoped would appear as part of the case and who has been referred to by Harris often in vitriolic and biting terms, did not appear as a witness.

Closing arguments in the trial are scheduled Monday