With the San Francisco Crime Lab no longer in operation, nearly 700 officers were trained to use portable kits to test for cocaine, heroin, and methamphetamine. The “presumptive” tests cost about $1 each and reduce the need for outsourced drug testing at $155 per case.

The field tests involve dipping a toothpick into the suspected substance, inserting it into a glass vial, and placing it in a plastic bag with a chemical. Based on color changes, the substance can be identified.

Once concern is that some legal substances are known to yield a positive result for illegal narcotics. There is also some subjectivity in interpreting the colors. A seven page manual was distributed to help officers properly implement the kits.

Police officials are optimistic, however, saying that field testing could reduce the number of lab tests from 14,000 to 4,000 a year, easing the strain on the crime lab once it reopens.

Source: The New York Times