For the past decade, Allegheny County crime lab technicians have matched evidence in gun cases at a rate that is among the most prolific in the country.

The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives honored the lab yesterday for its 1,500th positive identification of a firearm using the National Integrated Ballistic Information Network, a nationwide computer catalogue.

The lab ranks 12th in the country in the amount of gun evidence entered into the system and fifth in number of matches -- a sign that it is one of the most effective labs in the country, said Corey G. Hill, eastern regional coordinator for the bureau. The four labs that have made more gun matches are from much larger metropolitan areas.

Announced at a news conference headed by County Executive Dan Onorato, the honor was a bit of positive news for a lab that has been criticized heavily in the past few years for its backlog of cases that has led to delays in the court system.

District Attorney Stephen A. Zappala Jr. provided funding for smaller fingerprint labs run by municipal police departments, which have faced long waits in getting results back from the county lab.

"There's been criticism of the crime lab, but this proves how far we've come," said county police Superintendent Charles Moffatt. Without the lab's strong ballistics work, "we could not solve some of the cases we continue to solve," he said.

The seven staff members in the ballistics section enter bullets, fragments and shell casings into the national computer database, which can match them up with firearms evidence from other cases. This is possible because each gun leaves a unique signature on a bullet.

Sometimes discovering a link between two gun crimes can be the difference between a cold case and an arrest. And in court, physical evidence usually is more reliable than witnesses.

Early next year, the crime lab will move into the $22 million medical examiner's facility in the Strip District, but its current quarters can be tight.

"We're sitting on top of each other," Dr. Robert Levine, the head of the ballistics division, noted before Mr. Onorato jumped in.

"We don't call that cramped," the county executive said. "We call that being frugal with the taxpayers' money."