Last week the Massachusetts Supreme Court banned lie detector tests from use in criminal trials . Last week, the state Supreme Court banned lie detector tests from being introduced as evidence in criminal trials. Massachusetts had been one of the last states that allowed defendants to use polygraph results to support an alibi . Many states allow polygraph evidence if the prosecution and the defense so agree . The Massachusetts court said that experts said that there was a question as to their accuracy , and cited studies that showed accuracy rates varying from 50 to 95 percent . Last year a federal law severely restricted the use of polygraphs in the private sector . Companies that make the polygraph instruments were hit hard by that law .
Last week the Massachusetts Supreme Court banned lie detector tests from use in criminal trials . Massachusetts had been one of the last states that allowed defendants to use polygraph results to support an alibi . Many states allow polygraph evidence if the prosecution and the defense so agree . The Massachusetts court said that experts said that there was a question as to their accuracy , and cited studies that showed accuracy rates varying from 50 to 95 percent . Last year a federal law severely restricted the use of polygraphs in the private sector . Companies that make the polygraph instruments were hit hard by that law .