Carnegie Mellon University


State Police received a tip that a shipment of illegal drugs, possibly "nocaine", was being delivered to a known drug dealer. The informant said that the drugs were being driven into the state via Route 36 in a green, 1993 Pontiac with a large dent on the right front fender and a crack in the passenger-side mirror.

Police stopped a car that fit such a description. The driver gave the troopers permission to search his car, saying that he had nothing to hide. They found two bags of groceries. One bag contained a leaking box marked corn starch. It was confiscated and sent to the State Police Lab for analysis.

The motorist insisted that he had just purchased the corn starch, but could not produce a receipt. When confronted with the fact that his car matched exactly with the description given by an informant, he said that he must have been set-up by a disgruntled friend.

Is the motorist delivering illegal drugs, or does he just need new friends? Analyze the white powder and find out.


One of the ways scientists identify substances is to observe the way that they react with other substances. Some substances tend to react in a similar way; others may react completely differently. These similarities and differences help scientists determine what a substance might be.

By running a series of tests on a group of substances that appear to be similar, the differences in how they react can be used to tell them apart.  In our case, all of our substances are white powders. By testing them all with the same test substances, we can observe the different ways in which they react to each test and use these differences as a means of possible identification. Two substances which appear to be similar and react identically to all of the tests are "probably'' identical.

These test procedures, called standardized tests, must give characteristic results and be established prior to examining an unknown.  And there must be enough tests to rule out the possibility that the unknown is something else.

Four different white powders representing drugs will be tested in addition to the suspected “drug”. We will also test corn starch to determine if the motorist was telling the truth.