State: Small Percentage of Breath Tests Invalid

BOSTON (AP) _ State officials say there is no evidence breath test machines used to test for drunken driving in Massachusetts are working improperly.

But a review by the Massachusetts Department of Public Safety of 39,000 breath tests did reveal a small number _ fewer than 150 _ to be invalid because the instruments were not calibrated according to Massachusetts regulations. The department blamed the invalid results on ``operator error'' and not a malfunction with the machines themselves.

Secretary of Public Safety Daniel Bennett says his office is working with local district attorneys to identify cases that might have been affected.

Several prosecutors had suspended the use of breath-test evidence pending the state review and the Massachusetts Bar Association had previously called for an independent review into the reliability of the tests.