When a shark bites, it leaves a distinctive array of teeth marks.

Scientists could guess at the type or size of the shark behind that bite.

Researchers now say they've developed a forensic technique to more precisely narrow down the potential suspects, determining, for example, whether it was a 4-foot blacktip or a mako or a bull shark.

That could be useful for anyone who deals with the aftermath of shark bites, both human victims and companies wanting to protect expensive underwater equipment from the predators.

"It goes beyond the obvious because humans don't get bit that often," said George Burgess, a shark researcher and director of the International Shark Attack File. "But sharks also bite other animals, manatees and dolphins, and sharks also bite undersea cables, scientific instruments and military equipment that are in the sea, so this information could have application in many different areas."

For example, sharks were blamed for damaging deep-sea fiber-optic cables on the ocean floor in the 1980s, according to the International Cable Protection Committee, based in the United Kingdom. The cables are now better shielded.

The new forensic technique, published recently in a scientific journal, offers a set of formulas for measuring and comparing teeth marks left by a shark.

Researchers from the University of Florida and University of South Florida studied hundreds of shark jaws, both dried museum specimens and freshly caught sharks, to measure the tooth sizes, distance between the teeth, and size and curvature of the jaw.

They matched the bite patterns and measurements to the size of the shark, with specimens from 10 different shark species. Samples included a jawbone measuring 3 feet in circumference from an 18-foot great white shark, as well as an array of mako, bull, tiger, sandbar and blacktip sharks.

Using those measurements, the study confirmed that the 2003 shark attack on surfer Bethany Hamilton off Kaua'i involved a 14- to 15-foot tiger shark. Hamilton was surfing with friends at dawn at the Tunnels surf break in Hä'ena when the shark bit off most of her left arm.

Some of those scarred by a shark, Burgess said, want to know more about the shark that struck them. "For some, it can provide some closure, while for others it's a matter of bragging rights."