sentences:  [Senate Report 106-404, p. 61, September 8, 2000] The program is described as emphasizing non-intrusive environmental applications of the technology, such as daily testing of doorknobs to determine what drugs are most prevalent.However, a local news report emphasized that the testing can be done on students' personal items, such as like book bags, pencils, door handles, keys or cell phones, and that when evidence of criminal activity is found the school is legally required to inform police.Nonetheless, initial positive results are not taken seriously, because false positives can result from chemical cross-reactivity, second-hand contact such as a handshake with someone who has handled a drug, or lingering environmental contamination.