A Fairfax County judge yesterday ordered a former official of a national education organization committed to a state mental hospital as part of his sentence for the May slaying of an acquaintance he supposedly believed was having an affair with his wife.

A jury had recommended a 16-year prison term for Roosevelt Ratliff, 39, the holder of a doctorate degree from Stanford University and the former associate director of the Association for Supervision and Curriculum Development, an Alexandria-based national education group.

Ratliff was convicted in September of killing Kenneth H. Wise, 39, a man Ratliff barely knew, according to trial testimony. Ratliff shot Wise in the back in midafternoon outside a Franconia 7-Eleven store. Ratliff's attorneys argued that he had delusions that Wise was having an affair with his wife and had asked the jury to find him innocent by reason of insanity.

Judge JoAnna L. Fitzpatrick postponed sentencing for Ratliff and ordered him committed to a state mental institution.

"I do not believe, with your knowledge, that you will receive much help in the prison system as we see it today," Fitzpatrick said. She warned, however, that if the treatment he received at the state facility is not successful that "in 16 years when you're released from prison we're all in trouble."

Fitzpatrick told Ratliff: "A man is dead for no reason and nothing I've seen would indicate this wouldn't happen again the day you were released."

Fitzpatrick, who said the "jury's verdict is fair," will impose the sentence after Ratliff undergoes treatment at the state facility. The jury had recommended a 15-year prison term on a second-degree murder charge and urged an additional one-year sentence on a separate charge of using a firearm in the killing.

Assistant Commonwealth's Attorney Thomas Gallahue fought Ratliff's attorney's efforts to commit him to a mental institution rather than send him immediately to a state prison.

"Are we going to treat Dr. Ratliff--because he's got a number of degrees--differently than someone who is illiterate?" asked Gallahue.

Ratliff's attorney, Marvin Miller, argued that psychological tests by several doctors indicated Ratliff "does have a mental illness . . . You don't find PhD's doing things like this in the middle of the afternoon, in broad daylight to a neighbor."

Fitzpatrick said letters received by the court from Ratliff's professional acquaintances and friends described him as an extremely bright man.

"He was the most exemplary citizen in the county, with not even a parking ticket," Fitzpatrick said the letters indicated.

"I have more than ample grounds to believe you are mentally ill," she told Ratliff.

She added that she was concerned that "you don't think you've done anything wrong."

That prompted Ratliff, dressed neatly in a gray three-piece suit, to stand slowly and reply, "I am deeply remorseful. I do feel I've done something wrong."

Fitzpatrick responded: "Kenny Wise is dead and he didn't do anything."

Wise, of the 6300 block of Hillar Court in Fairfax, was a Metrobus driver. Ratliff shot him in the back as he walked out of the store carrying a bag of groceries, according to court testimony.

During the trial prosecutors produced evidence they said refuted claims that his actions stemmed from a mental disease.

They said he appeared calm before and after the shooting and that, after attacking Wise, Ratliff returned home to dictate a letter of resignation from his job, then phoned police about the shooting.