Drug smugglers are known for their skill at disguising cargo, but technology is making it easier for customs inspectors to spot suspicious shipments.

"Over the last three or four years, U.S. Customs has become more sophisticated at identifying drug trafficking lanes," said Bill Ansley, a vice president of Tower Group International Inc., a broker and forwarder in Atlanta.New Technology Responsible

"They've been successful at reducing delays in releasing commercial cargo," Mr. Ansley said. Primarily, it's because of new technology. "New selectivity systems make it easier to identify candidates."

The Port of Miami, Mr. Ansley said, has the most advanced screening systems in the country. With the dubious distinction of being the country's main gateway for drug traffic, Miami has long employed more customs inspectors and undercover agents than any other port of entry. Many breeds of dogs, from German shepherds to cocker spaniels, are routinely called in on sniffing assignment.

Special funding over the last two years, under the efforts of district director D. Lynn Gordon, however, has enabled Miami to install a number of technological improvements.

Mobile X-Ray Units

Customs inspectors in Miami move cargo from the ship to the inspection center on conveyor belts and automated rollers. "Just a few years ago we moved containers with nothing but manpower," said David McKinnen, chief contraband enforcement team inspector at U.S. Customs in Miami.

Inspections were carried out at that time by crowbar and hammer, Mr. McKinnen said. Now most seaports have mobile X-ray units that are brought in when an inspector wants to probe the cargo. Later this year the Port of Miami will install a larger, fixed X-ray unit.

This unit will not be large enough to inspect an entire container. Pallets will be unloaded and X-rayed individually.

"To see if anything is concealed in the structure of the container, we'll run detector dogs over it, then drill holes if the dogs find anything," Mr. McKinnen said.

The most significant advance in speeding up the inspection process, however, is the increasing use of computerized transactions between the forwarder, carrier, customs inspectors, and broker. All ports of entry in the U.S. have begun to rely on the Automatic Broker Interface system to determine which shipments should be inspected.

Customs officials are now able to decide whether to inspect a shipment before it arrives. Advance manifests, transmitted by the carrier to Customs, give the inspectors a profile of the cargo and its origin.

More Intensive Searches

"We used to try to inspect as many containers as possible," said John P. Leyden, assistant area director for inspection control for Newark Customs, which oversees inspection at the Newark Airport and the Port of New Jersey. ''Now we're looking to do fewer, but more intensive searches. In the past six to eight months, we've been able to use targeting procedures to make this possible.

In order to outwit drug smugglers, customs inspectors have to constantly update the criteria they use to weed out suspicious cargo, even electronically. Inspectors will not discuss specific profiles of such cargo, since drug dealers quickly change any technique that they know is known to customs. Nevertheless, Mr. McKinnen said, Customs is able to keep computerized records on shippers that have been involved in suspicious activities.

"If we do our research on the cargo and nothing derogatory comes up on the computer, we let the cargo go," he said.

Mr. Leyden said that Newark Customs is now able to release 25 percent of the cargo that comes in without any paperwork. "We look at data on 7 percent of the cargo, but we're looking at only 7 percent of the freight physically now," he added.

With this system, Customs is able to tell the customer who is waiting for the cargo exactly when he can expect it to be released. "Before the freight arrives, the customer will know whether it is going to be released immediately or not," Mr. Leyden said. "So if there is going to be a delay, he'll be prepared for it."

'CET Hold'

The customer and the broker do not know right away why the cargo is being held. Through the computer system, Customs lets the carrier, but not the broker, know if a shipment is going to be placed on what is called "CET hold," meaning inspection by the contraband enforcement team.

The inspection, according to brokers, takes about a day, and the broker is told only that the cargo is getting an intensive examination.

Customs might decide to examining the cargo for many different reasons. The country of origin might be improperly marked on the goods, or the shipment might be improperly declared and classified on entry. Customs officials try to inspect the shipments coming from first-time exporters so that they can develop a profile on the shipper.