be cut from the welfare rolls.

While this will reduce the welfare outlay, which the county intended, it is unclear how many of the people who fail to show up or come up as a match on the system are actually double dippers. "We don't know how many," said DeStefano. "There is no way to tell how much duplicate aid is going on."

Another element making the payback of such systems difficult to determine is that there is some deterrence from double dipping, which is difficult to quantify in dollars saved because the number of people deterred would remain unknown.

SHARED DATABASES

Because Sacramento County is alone in using hand images, they are unable to check other counties for persons getting double benefits. This will become important as more counties begin to use technology for cracking down on double dippers, because the counties will need a common reference for image comparisons.

The state plans to deploy a matching system once testing and evaluation of Los Angeles County's fingerprint system is finished, said Sidonie Squire, spokeswoman for the state Department of Social Services. She added that there is no set timetable for implementation.

If the system used by Sacramento meets the requirements being developed by the state, then the hand imagers may be used not only by Sacramento but other counties as well.