>> a full-time criminal investigation team has been set up at angola with drug testing capabilities. >> since we don't -- it could have been positive for marijuana, but we may not have enough substance, so we'll call this test an inconclusive test. >> just because it didn't test positive doesn't necessarily mean it wasn't being used for car nottics. it just means once it's been smoked, it's harder to test. >> but he'll still be charged with contraband for the ink pen because he used it for a source other than what it's supposed to be used for. >> today's second catch appears much more promising. >> that's marijuana. >> the investigation unit is led by retired police officer colonel ken norris. >> we're like an internal unit within this prison. we investigate everything involving the correctional officers as well as the inmates. that's everything from, you