BOOK REVIEW : Why It’s Hard to Pull Off Murders : BONES: A Forensic Detective’s Casebook <i> by Douglas Ubelaker and Henry Scammell</i> ; An Edward Burlingame Book/HarperCollins; $23; 320 pages

Earlier this month a pair of human arms washed ashore separately: one at Venice Beach, the other near Marina del Rey. The police almost immediately identified the person to whom they had belonged, but this didn’t surprise me. I had just finished reading “Bones” by Douglas Ubelaker, curator of anthropology at the Smithsonian Institution since 1971.

People still get away with murder, Ubelaker reports, but it’s getting harder all the time thanks to the recent union of anthropology and the law in the hybrid science of forensic detection.

The seeds for that union were sown in 1962, when J. Lawrence Angel, one of the century’s great anthropologists, joined the Smithsonian and offered his expertise to the FBI. The 1960s were exactly the right decade to usher in a new scientific approach to detective work. The public had begun to openly admire science, and physical anthropologists, who had previously focused on the remains of extinct civilizations, realized they could become more involved in the world around them.

Most people today, including your run-of-the-mill murderer, know that it’s impossible to prosecute a murder case without an identifiable corpse that shows signs of an unnatural demise. The most common way of shrouding that identity is to cut off fingertips (or whole arms), eliminating telltale prints. Savvier killers also know it’s a good idea to dispose of the teeth, preventing identification via the dental hot line.

Few, however, know that there is another unique marker inside the skull. In the sinus cavity, Ubelaker tells us, there is a filigree butterfly embedded in the bone behind and above the brow which can be recorded in a CT scan, a type of imaging that is increasingly being stored in hospital files all over the country. Add to that DNA evidence, and it becomes clear that even a well-informed murderer will be hard put to conceal a victim’s identity.

In “Bones,” Ubelaker recounts his work as an anthropologist (digging up burial jars, for instance, in Guayaquil, Ecuador) and as a forensic detective, examining the odd skull and leg bones turned over to the Smithsonian by the FBI.

Ubelaker sees his vocations as mutually beneficial: To explain the deaths of 14 mutilated male victims he found in an ancient burial site in Peru, for example, he used the same skills that he applied in a forensic examination of bones found recently on the side of a Virginia road.

“Bones” is a good title, for with few exceptions, bones are all that remain of an unembalmed and unprotected body after a remarkably short time on top of, or underneath, the ground. Needless to say, the details of this decomposition are not for the squeamish. Maggots of many varieties seem to crawl through the pages as Ubelaker details their role in the ecological cycle.

Most of the modern remains Ubelaker examines were those of young people who turn out to have been the victims of greed or anger. A memorable few, however, were old and left to die alone, victims of neglect--or, from an anthropological perspective, victims of an uncaring society.

Like an unedited diary, “Bones” is filled with fragments of stories about the author and the lives of those he examines. But the form is limiting, and in the end “Bones” is no more than an interesting ramble. I was left admiring the author’s joy in his profession but regretting that he could not make the whole more than a string of scattered parts.