Virginia has a statute allowing marijuana field testing testimony into evidence:

“In any trial for a violation of § 18.2-250.1, any law-enforcement officer shall be permitted to testify as to the results of any marijuana field test approved as accurate and reliable by the Department of Forensic Science pursuant to regulations adopted in accordance with the Administrative Process Act (§ 2.2-4000 et seq.), regarding whether or not any plant material, the identity of which is at issue, is marijuana provided the defendant has been given written notice of his right to request a full chemical analysis. Such notice shall be on a form approved by the Supreme Court and shall be provided to the defendant prior to trial.” Va. Code § 19.2-188.1.

Here are my mostly off-the-cuff recent comments on this matter to the Virginia Association of Criminal Defense Lawyers’ listserv, on this topic:

I am trying to transcend being burnt up that any judge will allow in marijuana field test evidence at trial, particularly where the defense has obtained an order for the plant material to be tested. Here are a few thoughts:

• The field test calls for expert testimony. Were there expert testimony, the field test hopefully would be exposed for its holes.
• Just as cops are not permitted to give conclusions about the meaning of field sobriety tests, neither should cops be permitted to give interpretations of the meaning of field tests. If cops are going to be able to testify about field tests, it should be limited to saying something along the lines of: “I took a medicine dropper, inserted it into a bottle (argue that it is inadmissible hearsay for the cop to read out the name of the test kit used, nor the expiration date, without bringing the same one to court), put a drop on a portion of the green leafy material, and saw that green leafy substance turn to this or that shade of purple (or whatever other result) after I did so.”To permit the cop to testify that the material tested positive for marijuana brings in inadmissible hearsay and expert testimony about what on earth the change in color of the marijuana from adding the test chemical means.
• Maybe lawyer Jim Shellow will have more ideas. I wrote about him yesterday about his command of challenging drug chemist analyses.
• As mentioned in my foregoing blog entry, Melendez-Diaz mentions Shellow. These field tests involve testimonial evidence, geared towards testimony at marijuana trials. Sure, the requirements of the unavailability of the witness in Melendez-Diaz v. Massachusetts, 129 S.Ct. 2527 (2009) does not fully apply when the field testing officer is present, but the whole field testing scheme is testimonial, and the prosecutors do not present the testimony (nor even written certifications) of the people who manufacture nor approve the field testing kits for accuracy. Of course, that is also a problem when prosecutors try presenting results of Intoximeter results without the testimony nor certified letters from the people certifying the Intoximeters.
• Although I have had judges discount caselaw from other jurisdictions — unfortunately sometimes without even knowing what is in the decisions — two opinions to keep in the back pocket relating to the above issues, and to DWI cases, are:
  • Blackwell v. Maryland:, (only expert testimony is allowed to present testimony on the administration of the horizontal gaze nystagmus test, so only expert testimony should be permitted to allow police to talk about their procedures and observations with field tests of suspected marijuana);
  • U.S. v. Horn, 185 F. Supp. 2d 530  (D.Md. 2002) (helping to cut down field sobriety tests towards the junk science that they are).