However, some inmates' relatives and friends and civil rights organizations are also complaining that the devices can keep law-abiding citizens from visiting loved ones. Officials at the prisons use hand-held vacuums to vacuum visitors' hands and pockets. They then remove the vacuum's filter and put it into a machine called an ion scanner, which can detect as little as one-billionth of a gram of narcotics.
Officials say a clean filter is used every time.
John Byler, spokesman for the federal prison in Tucson, said the machines stop visitors from smuggling in drugs. That not only reduces illegal behavior, but also improves safety for corrections officers and for the federal prison's 751 inmates here, officials said. In 1997, before the machines were used, roughly 1,000 random drug tests were conducted among inmates at the Tucson federal prison. At the state prison in Perryville, which is testing several scanners, the number of positive drug tests among its roughly 2,000 inmates dropped to 2.5 percent last year from 3.2 percent in 1999. Visitors who test positive at federal prisons are turned away for at least two days and can be barred for longer periods if drugs are detected on them repeatedly.