Negative Urinalysis Results
Information on negative urinalysis results in post-trial processes:
- A urine sample containing drug metabolites in
concentrations below the regulatory cut-off level for positive results will be declared negative, even though the sample may indicate drug use.
- Negative test results are usually inadmissible. United States v. Johnston, 41 M.J.13 (C.M.A. 1994). Judge did not abuse discretion by excluding defense evidence of urinalysis test which was negative for the presence of marijuana three days after last charged use of marijuana. Admission of results of a negative, defense
conducted, radioimmunoassay (RIA) test would have been too confusing. The proper testing methodology was GC/MS, and the RIA test showed the presence of marijuana (but below the cut-off level). The C.M.A. stated that the Mil. R. Evid. should be used to determine if negative test results are admissible and overruled United States v. Arguello, 29 M.J. 198 (C.M.A. 1989) (which prevented the government from using negative test results because such use was contrary to regulation).
- Use of negative test results is permitted in the Coast Guard. United States v. Ryder, 39 M.J. 454 (C.M.A. 1994), rev’d on other grounds, 515 U.S. 177 (1995). Government’s introduction of “negative” test results, which showed presence of marijuana, but at amount below cut-off, was not plain error. Results were used to corroborate testimony of witnesses who saw accused smoke marijuana and Coast Guard Regulation did not prohibit use of such test results.