The charred remains, delivered to the Fairfax Hospital morgue, were described by police as a driver whose small truck had gone up in flames. At least that's what identification papers found at the scene had led them to believe.

But James C. Beyer saw immediately that what lay before him was something else entirely -- the crispy leftovers of a pig.

"We made the remark while we were doing the autopsy that this would make a nice ham sandwich," said Northern Virginia's longtime medical examiner. "And it would. It was good Virginia ham. We recognized {the remains} as ham bones."

Several times a day, the gray-haired, bass-voiced physician bends over a cold human body in the brightly lit morgue across the hall from his office. Appointed medical examiner in 1972, and one of eight pathologists employed by the State Health Department to perform autopsies, he is a veteran of more than 20,000 autopsies. In 1986 alone, Beyer and his deputy, pathologist Frances Field, performed 1,299 of the 6,020 autopsies carried out by the state.

"I like to know why people died," said the Illinois-born Beyer, 69, dressed in a baggy blue scrub suit and black wing tip shoes as he sat recently in his ground-floor office amid piles of textbooks and souvenirs. "I like to solve that mystery."

From Beyer, who combines the practice of medicine with the intuition of the detective, police learn invaluable details in difficult murder cases: the thrust of a knife (up, down, right-handed or left-handed); how close a gun was held to a victim; the approximate time of death, and how long it took for the victim to die.

One of 575 forensic pathologists in the country, Beyer has become a recognized expert on gunshot wounds, an early observer of coronary heart disease and a contributor to the development of protective gear for American soldiers in Korea and Vietnam.

On local turf, he is known for more than his medical expertise. He is an avowed pack rat (he still has the ham bones in his freezer, "just for the oddity"). A wrestler in his youth, he once wanted to collect animals in the Amazon. He has a bug named for him and takes glee, as one prosecutor put it, in scaring "to death" rookie homicide cops at their first autopsy.

"Dr. B," as he is known by police and prosecutors alike, is at his crustiest during the rookies' first autopsy, scowling at the novices' "totally ridiculous" questions, growling one-word answers and generally intimidating them out of their wits.

"I wouldn't put him at the top of the list as far as public relations goes," said Robert Carrig, a longtime friend. "And if he sees {a novice} getting a little wobbly, he may make {the autopsy} a little worse just to harass them. He's kind of like an artist who plays to the audience."

"He scares all these young cops to death," said Prince William County prosecutor Paul B. Ebert.

Smiling, Beyer says "a few" cops have fainted on him. "There's a certain reason" for his put-on gruffness, he said. "Many times it's because . . . the questions they ask are totally ridiculous." For example, " 'Are you going to do a blood-alcohol {test}?' Blood alcohol is done in every case we do. So there's no need to ask.

"Oh, I don't give them a hard time," he said. "I indoctrinate them so that they'll accept what they're going to see. I haven't had any complaints."

Novices soon learn what their older counterparts already know. "Dr. B" is "nothing like his bark," as Arlington Detective Frank Hawkins put it. "I have nothing but respect for him."

"The morgue is his whole life," Carrig said.

For a number of local prosecutors, Beyer's help has proved invaluable.

In a recent case handled by Ebert, Beyer estimated that the victim took three to five minutes to die as she was being strangled. The defendant, at trial, said it was not premeditated murder.

"I stopped my {final} argument and let the jury look at the clock for three minutes . . . . {It} seemed an eternity," Ebert said. "I think it helped get first degree murder . . . . {The defendant} had enough time to stop and think about what he was doing."

In another Prince William County case, police brought in a victim they described as an apparent suicide by hanging. But Beyer discovered a small-caliber bullet in the back of the woman's head, hidden by her long, black hair.

"He said, 'What the hell is going on down there! I found a bullet in this head!' " said Prince William County Deputy Police Chief Charles Deane, who took the medical examiner's call. "He was upset that we had not detected that sooner. We didn't know there was a bullet in the head until Dr. Beyer told us so."

Arlington Detective Chuck Shelton speaks from experience when he says Beyer enjoys "throwing you a curve." He recalled the time when Beyer, examining the contents of a victim's stomach in an attempt to determine time of death, picked some up. "I swore he actually tasted it," Shelton said.

"It took me a couple of seconds to recover," he said, after realizing Beyer had not actually conducted a taste test.

Prosecutors love Beyer for not equivocating on the stand. "I've never seen defense make any inroads on his cross-examination," said Alexandria Commonwealth's Attorney John E. Kloch. "Dr. Beyer always has his medical ducks in a row." And defense attorneys praise him for his neutrality and accessibility.

Born in Rockford, Ill., Beyer graduated from St. Ambrose University in Davenport, Iowa, where botany and entymology were his first loves and his hobby was collecting insects. That was when he discovered the midge, a tiny fly-like insect, that now bears his name.

Later, intrigued by the comparative study of human and animal tissues, Beyer applied for an expedition grant to the Amazon Basin to collect animal specimens. "But that fell through, so I elected to study human {tissues}," he said.

Beyer, who is married and has four sons, earned his medical degree summa cum laude from Chicago's Loyola University Medical School in 1946, following up with a master's in anatomy. Joining the Army, he attended the Armed Forces Institute of Pathology and traveled twice to Korea in the 1950s as part of casualty survey teams. Their examinations of GIs killed in battle were used to develop more protective boots, helmets and uniforms. This work, and a similar survey in Vietnam in 1963, led to Beyer's publications on gunshot wounds.

Autopsies on soldiers in Korea also offered him the opportunity to examine coronary heart disease long before it was widely understood. An article he co-authored on this subject in the 1950s was recognized as a landmark last year by the Journal of American Medicine.

In 1963, Beyer left the Army with the rank of major and became scientific director of research and development in the Army Surgeon General's Office. That year, he joined Arlington Hospital and for the next several years worked there and at Northern Virginia Doctors Hospital as a pathologist.

Nine years later, he was named medical examiner.

Asked about changes he has seen in his work, Beyer notes: "Twenty years ago, to talk about heroin and cocaine was practically unheard of. Today, you have to suspect it" as a cause of death, he said. And while he did not usually wear gloves for the external examination of a body, AIDS has changed that.

Among the textbooks in his office is a one with a chapter on "auto-erotic" deaths by Beyer and the late William Enos, his close friend and predecessor as medical examiner. Some individuals, Beyer explained, "believe that by producing some type of constriction in their neck and reducing the oxygen and blood flow to the brain they enhance their sexual satisfaction."

"Twenty years ago, we probably thought they were suicides; now we recognize them as accidents," he said. "That's the thing I lecture on primarily now . . . . I've graduated out of ballistics."

Beyer prefers doing autopsies on persons whose cause of death is not apparent. "It gives me an insight into the disease processes people have {when there are} apparently no known symptoms either to themselves, their next-of-kin and frequently not even to their attending physicians," he explained.

Families frequently request autopsies in such cases, Beyer said, indicating an increased acceptance of autopsies. "There was {in the past} a common impression that autopsies were a mutiliating procedure. People thought the body was randomly cut up and that {it} was no longer available for viewing at a funeral home."

Done properly, "the family would never even know it has been conducted."

Does he plan to be autopsied on his death?

"I haven't really thought about it," Beyer said.