Skip Sperber is a friendly neighborhood dentist who has been practicing in Clairemont since 1956. Nowadays he treats the grandchildren of his first patients, and nothing makes him happier.
But law enforcement officials here and across the country consider Skip little short of a secret weapon.
Consequently, Norman D. Sperber, 59, is a busy man. Besides his four-days-a-week practice, he's on call all day and all night as the forensic dentist for the San Diego police, the Sheriff's department, the district attorney and the coroner.
Sperber, an upbeat man who says his family and serving the community are his greatest joys, is one of the top men in forensic dentistry.
And he's a pioneer in bite-mark evidence, testifying in 56 felony cases since 1975. In the 48 cases in which Sperber testified for the prosecution, 46 ended in conviction.
Among his exploits:
- Linking a piece of cinnamon chewing gum left on a dusty dresser at a murder scene to San Diegan Patricia Beebe, whose teeth marks were especially distinctive because of a missing filling. Faced with the evidence, she pleaded guilty.
- Pulling the same trick in two other cases, once with a piece of partly eaten Swiss cheese and once with the remains of an American cheese sandwich.
- Ditto with an apple.
- And, once, with a suspect's teeth marks on a victim's nose.
"The type of material is important. A Saltine won't give good evidence. Runny or crumbly cheese, for example Camembert or bleu cheese, is not as good," Sperber said in a recent interview.
"Most bites we see are inflicted by the assailant on a victim of rape, child abuse or homicide. Occasionally a victim in a defensive posture also bites, and there is a minority of 'crossover biting,' " he said.
Phylip Peltier, an investigator in the district attorney's office, remembers Sperber's indispensable help in about 10 cases over the 12 years Peltier worked as a child-abuse investigator for the San Diego police.
"When children had bite marks, we'd call him in, and he would take photographs every 24 hours for a week. He'd take impressions of the marks, swab it for saliva to match blood types, and we'd come up with a list of suspects, sometimes as many as seven or 10.
"He would take impressions of everyone involved. Most of the time, they'd cooperate, not knowing how accurate it really was. Sometimes we had to get a court order, which basically amounted to a search warrant for your mouth, and he'd go down to the County Jail and do it," said Peltier.
'He's the Best'
"He's the best at what he does. He's just going to tell it like it is. And he has no limits on when you call him up. It's just endless work, and they call him all over the country," he said.
For his work, the county pays him the nominal fee of $75 per identification.
In the past few years, Sperber has once again been in the foreground in getting new types of evidence admitted in court.
This time, he's been pushing imprints of inanimate objects left on tissue: in one case, he testified about the imprint of an assailant's watch on a victims face; in another case, a telephone receiver left vital evidence behind.
But getting scientific and judicial acceptance in new areas can be rough going, as Sperber learned in the second trial of Craig Peyer, a former California Highway Patrol officer eventually convicted of strangling college student Cara Knott.
In that case, Sperber photographed the marks on Knott's neck and the rope prosecutors said was used.
"He noticed the same pattern in the ropes and marks, and he compared the distance between the braids on both photographs. He determined that it was the identical distance," recalls Paul Pfingst, then-deputy district attorney and the prosecutor in the case.
Advance in Law
"Unfortunately, it was a real advance in the law--no one had done this before, and the judge rejected it. I was pretty surprised, because we had really explosive stuff. Skip is a very powerful witness."
Said Superior Court Judge Richard Huffman, "There was not sufficient factual evidence that the marks shown in the photographs could be compared to the rope."
But Pfingst, like Sperber, is convinced that mark evidence is the wave of the future.
"Absolutely, there is going to be more mark evidence, not just of teeth. One reason is because more people are studying it, and more scientific consensus is important for admissibility," said Pfingst.
"There is an increasing degree of medical and scientific sophistication in criminal investigations, and this is one area that people are becoming more and more aware of.
"We're basically talking about indentations in tissue, and forensic odontologists have more training in that than virtually anyone else. I think the crossover applications are very obvious."
Says Pfingst of Sperber: "He's just a quality guy. It's amazing--I've seen a lot of pathologists, and he's the most entertaining, positive person that I've ever seen continually examine dead bodies. He's got a million stories."
Cluttered With Skulls
Sperber, whose office is cluttered with skulls and plaques of appreciation, majored in zoology and chemistry in college, and earned his degree in dentistry at New York University.
During the summers, he worked in the New York medical examiner's office, collecting samples from bodies.
"I always remember, dead men tell no tales, and it wasn't true: I began to figure out you could learn how they died and maybe why," he said.
In fact, Sperber helped convict Ted Bundy, a Florida serial killer blamed for as many as 50 deaths in the 1970s, who was sentenced to death largely on the basis of bite marks he left on a surviving Florida State University sorority student.
Lately, besides expanding his purview to non-bite indentations, he's been studying how to tell the ages of teen-agers and young adults by their teeth. His work in the area has already helped the district attorney decide whether to prosecute several suspects as juveniles or adults.
"I don't think I've made any mistakes," Sperber said.