When Minnie Champ identified her uncle's body Tuesday night, a group of anatomy students at Howard University Medical School lost a specimen they were about to dissect.

Casper Yeagin had been reported missing on Sept. 19, but doctors and police knew him only as "John Doe" during the two months that he lay unconscious at Howard University Hospital, and the two additional months during which his body traveled from the hospital to the morgue and then back to Howard University Medical School.

A police spokesman blamed it all on two apparent errors of omission by police officers. First, the officer who took the original report "didn't discover what he should have discovered." It was his responsibility to check area hospitals to see if anyone matching Yeagin's description had been admitted, according to the spokesman.

Second, after Yeagin's death on Nov. 3 someone at missing persons didn't check the list of noncritical missing persons; which contained Yeagin's name and age, the spokesman said.

A homicide investigator said yesterday that he had called the missing persons unit on Nov. 11 to see if they had a missing person report that fitted the description of the John Doe at the hospital. They said that they did not . . . I at that time assumed that there had not been a report made."

After he passed," said Dr. Linwood Rayford, assistant medical director of Howard University Hospital, "his remains were sent to the medical examiner's office." A month later, when efforts to identify him had been abandoned, "through some lottery or something they decided to award his body to one of the medical schools and it wound up at Howard," said Rayford.

Yeagin's sister, Pearlie Smith, had made the first report of his disappearance. The officer "asked me for a picture and I gave it to him," she said yesterday. "He said he would be back . . . but I didn't hear anything." Smith said she called again about a month ago, and an officer at the fifth district stationhouse told her that her brother still had not been found.

On Monday, Smith's daughter Minnie Champ called the missing persons unit to again inquire about her uncle, a call that brought a second visit to the family's home at 2408 30th St. NE by the same officer who had taken the original report. "He said 'yeah, I took that report myself' I called that in, I'm sure I called that in," myself' Champ recalled. "Then he made six or seven phone calls and I heard him say, 'You don't have any record of it?' They had no record of my uncle."

The result of this renewed inquiry was to put the missing persons unit on the case. That unit, a police spokesman explained, "doesn't get involved in investigating adult missing persons unless its critical."

Police finally connected their John Doe" with Casper Yeagin late on Monday, and Officer Jack Keithley of missing persons drove Champ to the medical school to make a positive identification.

Champ said she found her uncle, "up in the lab, you know (and they were) making experiments." But Rayford disputed this - "We had not done any, quote, experiments," he said, while acknowledging that the body "would have been used for dissection.

Yeagin, 68, a retired auto mechanic living on Social Security prior to his death, had lived with his sister on and off for 30 years, the family said. Hospital spokesman were unable yesterday to state the exact nature of Yeagin's illness, but said he died of "naural causes."

"I have been calling everybody," said Champ, "but I can't get any answers." Yesterday she went to fifth district headquarters hoping to learn just why her uncle had gone unidentified for so long before and after his death. She spoke to a station clerk, she said, "and he said, "They're still looking for him.'"