The farm-boy belly laugh gone, his cherubic face flushed with anger, the sheriff of Fairfax County told reporters last August he would not talk to them anymore.

He had just emerged from a grilling by the County Board of Supervisors on alleged misuse of inmates in his jail. He had walked out of the bosrd room to a standing ovation from his deputies. "I am finished, period, thank you," the sheriff had said to the board and he told reporters he meant it.

Last week, the farm-boy belly laught back and his cherubic face cherubic, Sheriff James D. Swinson leaned back in his swivel chair and said: "Now, you know that I never have refused to talk to reporters. That's one of the duties of a public official."

The good-natured difference between what the sheriff says and what the sheriff does are, in the view of mamy long-time sheriff watchers, vintage Swinson -- the style of an unabashed country boy oddly at home in Nothern Virginia's booming suburbs.

That style has helped the 66-year-old sheriff, who is nearing the end of his fourth term, establish himself as the best local Republican vote-getter in Virginia's largest and richest county. It helped him push the construction last year of a $4.6 million jail.

But it also had embroiled Swinson in a series of problems at the jail, out of which have come calls for his resignation and accusations that his style, however successful, blinds him to the needs of inmates in his care.

In the last five months, three county prisoners, all of them black, have died after being in Swinson's custody -- a fact that has outraged the sheriff's critics and brought new calls for his resignation.

The last death, that of 28-year-old Donald L. Ferguson last December, angered blacks in Fairfax and prompted an official investigation by county prosecutor Robert F. Horan Jr. It has also started Swinson talking.

"Going through the door of my jail is not a ticket to eternal life," he said of the death last week. "People have died there before land people will die there again. It doesn't make a rat's ass if I'm sheriff or if you're a sheriff."

That statement brought a shower of criticism from officials who have long wandered how well Swinson ran a jail. In Richmond, state Sen. Joseph V. Gartlan (D-Fairfax) called on Virginia GOV. John N. Dalton to dismiss Swinson from the state Council on Criminal Justice.

"Swinson had to have known that there would be gasoline on a roaring fire," Gartlan said, referring to already strained relations and blacks.

Three members of the Board of Supervisors said Swinson should be thrown out of office. Swinson retorted, that there are people who want to throw his critics out. "Knucklehead" is a term popular with Swinson for his critics.

"It is unfortunate that near the end of my career I have to go through so much of this horsesh. If you know yourself, that you've done what is right, it makes you feel good," the sheriff said.

Swinson, whose good-old-boyisms and generous girth are reminiscent of a hundred southern "shurfs" in television shows, was born near Warsaw, N.C. His father suffered from rheumatism and Swinson, forced to help out as the oldest of six children, learned at the age of 11 how to plow with a mule.

Jesse Swinson, the sheriff's brother, also remembers that his brother Jim was a crack shot with a shotgun and a boyu who enjoyed discipline.

Swinson joined the Marines in 1930, and stayed for 30 yars. He rose to lieutenant colonel because, his brother said, "Jim was a typical Marine; he was the kind who would iron his shoestrings." He fought in World War II and Korea and maintained a spotless record, according to the Marines.

When Swinson left the corps in 1960, he sold Ramblers in Northern Viginia until he was elected sheriff. Billing himself as a reformer, he narrowly defeated Democratic incumbent John E. Taylor. Once in office, SWINSON HAD LITTLE TROUBLE DEFEATING CHALLENGERS. His convincing public speaking style, his ties to the county Republican Party and hisuse of deputies to help him campaign have made him unbeatable, according to Republican officials in Fairfax.

Still, the sheriff who is paid nearly $42,000 a year, has often had to defend himself against his critics.

In 1969, a federal court order forced the desegreation of Virginia jails. Swinson, the last sheriff in Northern Virginia to integrate his jail, said he had kept races apart for their own "comfort and safety."

That same year, Swinson was criticized for running the only jail in the Washington area where juveniles who misbehaved faced solitary confinement on bread and water.

"They can misbehave at home. They can misbehave in shool. They can misbehave in the streets. But I'll be damned if they're going to misbehave in jail," Swinson said at the time.

During his four terms, Swinson has had four chief deputies, three of whom have quit or been fired under conditions described as "strained" by courthouse observers.

Former chief deputies Himes W. Bolinger and Myron L. (Bud) Greenquist both left their jobs, according to sheriff's department sources, because they could not gain control over operation of the jail.

"The sheriff lets the people in the jail do what they want," said Greenquist, who is considering running this fall for Swinson's job. Other authoritative sources confirm a lack of control by th sheriff over jail operations.

The recent controversy over inmate deaths in the jail which Swinson last week called a "goddam witch hunt," has made the sheriff particularly upset, he said.

"I have campaigned for years for an alcohol detoxification center in Northern Virginia," Swinson said. "No one has greater sympathy for the plight of the inebriate than I do."

Swinson, who has sign in Latin in his office that says, in translation, "Don't let the bastards get you down," has told many friends he will not be running again for sheriff. He has had enough, friends say.

The sheriff said last fall that sooner or later he can accept any criticism. "That's the price you pay for being number one," he said.