Law enforcement agencies and human rights groups frequently disagree over such matters as the treatment of prisoners. The latest example involves the use of what Amnesty International calls "stun belts" and the Bureau of Prisons refers to as "custody control belts."

Whatever the name, the devices are worn by prisoners and, when activated, deliver a 50,000-volt shock that lasts for eight seconds, causing severe pain and incapacitating the wearer. In a recent report, Amnesty International argued that "the use of the stun belt, even when not activated, constitutes cruel, inhuman or degrading treatment or punishment as outlawed under international law."

It is not clear how extensively law enforcement agencies use stun belts. They are used most often when prisoners appear in court or are being transported. According to the Amnesty report, a telephone survey earlier this year found that 20 state corrections departments, including the Maryland and Virginia prison systems, authorize the use of the devices. The organization estimates there are more than 1,000 belts in circulation in more than 100 jurisdictions.

The belts are non-lethal weapons, the type of device that groups such as Amnesty normally would endorse. But in the case of stun belts, the organization argues that international standards "state that new weapons must be 'carefully evaluated' and their use 'carefully controlled.' The U.S. authorities have failed to live up to this standard as electro-shock weapons have proliferated around the country's law enforcement agencies . . . without rigorous independent testing, evaluation and monitoring."

Quite naturally, law enforcement agencies tend to emphasize the non-lethal aspect of the belts. Only two federal law enforcement agencies--the Bureau of Prisons and the U.S. Marshals Service--use them and neither is apologetic about it.

According to Todd Craig, chief spokesman for the Bureau of Prisons, the agency has fewer than 40 of the belts and they are used only with inmates at the bureau's 12 high-security prisons. Only the wardens of those prisons can authorize their use.

"Our policy is to use custody control belts to prevent escapes, loss of life or grievous bodily harm," Craig said. "Anytime we can use less than lethal technology to carry out our public safety mission we will do so."

He said the bureau began using the belts in 1994 and so far has not activated one to jolt a prisoner. That, he said, "reinforces our belief that it is an effective deterrent to high-security inmates."

The Marshals Service began using the belts in 1996 and has more than 100 of the devices, said Bill Licatovich, a spokesman for the agency. Belts have been activated no more than once or twice since then, he said.

"Often we are dealing with dangerous people--dangerous not only to us but to the general public and sometimes themselves," Licatovich said. "We need to control them and stun belts help us do that."

MOST WANTED: When the Federal Bureau of Investigation added two new names to round out its list of the 10 Most Wanted Fugitives last week, it also provided a fascinating glimpse at the history of the program.

It began in 1950 as the result of a newspaper story the year before. A reporter for the now defunct International News Service asked the FBI for the names and descriptions of the "toughest guys" the bureau would like to apprehend. The resulting story generated so much interest that then-FBI Director J. Edgar Hoover was inspired to start the 10 Most Wanted program.

On March 14, 1950, Thomas J. Holden, who was wanted for murder, became the first person placed on the list. He was captured 15 months later. By now, a total of 456 fugitives have made their way onto the list, and 428 of them have been apprehended or otherwise located. Only seven of the Top 10 fugitives have been women.

Average time on the list is 316 days. The record for eluding law enforcement officers while on the list is still held by Charles Lee Herron, who was wanted for the murder of a police officer. His name went on the list on Feb. 9, 1968, and he remained free until June 18, 1986.

But Herron's record is under serious assault by Donald Eugene Webb, who was placed on the list on May 4, 1981, for the murder of a Pennsylvania police chief. If Webb is not located by the end of September, he will be the new record-holder.

Top 10 fugitives have been located in every state except Alaska, Delaware and Maine. California, where 58 fugitives have been located, leads this category followed by New York with 38.