A urine specimen is preferable to a blood specimen because the drugs (Rohypnol, GHB, and other rape drugs) and their metabolites can be detected in urine for a longer period of time. If the victim ingested a rape drug within 96 hours prior to reporting the assault or receiving medical treatment, a urine specimen of at least 30 milliliters, but preferably 100 milliliters, should always be collected and delivered to the crime lab for a full or comprehensive drug screen. It is important to determine whether the jurisdiction's lab is capable of conducting the needed tests or whether the samples must be sent out of State for testing, possibly to the FBI lab. Chemists, toxicologists, and pharmacologists historically have testified in drug trials about their analyses of the particular drug or drugs involved in the case. In a drug-facilitated sexual assault trial, these experts will also testify about their analyses of the drug used in the rape of the victim. In addition, these experts can testify about how the particular drug used affects the body in general, how the victim's symptoms are typical of someone who has ingested this drug, and any lack of a positive toxicological result in the case. Should the defense use an expert witness, it is important to determine the background of the defense expert prior to cross-examination, particularly whether he/she has any actual experience in analyzing forensic biological specimens specific to drug-facilitated sexual assaults. 8 notes