True Guarnieri Ayer, LLP
Call For A Free Consultation

This Is An Advertisement

Field drug tests often unreliable

Recent incidents in New Jersey and Florida have shown that field drug tests used by police to determine if a substance might be illegal are often unreliable, making the millions of Americans charged each year with illegal drug possession prime candidates for criminal defense.

However, almost every person arrested and charged with drug possession based on roadside drug tests agrees to a plea deal before any criminal defense can be mounted.

The problem with the tests

Roadside drug tests have been known to be unreliable since the mid-1970s. They usually consist of a plastic pouch with vials containing chemicals. An officer will open the pouch, put the suspected drug in the vials and see if the chemicals change color. Depending on that reaction, the officer will make an arrest and conduct a search.

The areas where such a test could go wrong are numerous:

  • Some tests use vials with cobalt thiocyanate, which turns blue when exposed to cocaine, methadone, acne medication and 80 other substances including household cleaners.
  • Some tests require officers to put the suspected drug in one vial, then another and then a third for an accurate reading. If the officer uses the vials in the wrong order, the result is invalid.
  • Cold weather and hot weather can affect the tests.
  • The officer must determine if the color of the chemical in the vials has changed, but the tests are often conducted in areas with poor lighting or with flashing lights.
  • No agency regulates the manufacture or sale of the tests and no records are kept on their use.

Because the tests are so unreliable, the results are not used in trial as evidence. Police instead use results from a lab where scientists have examined the evidence under a mass spectrograph.

Plea bargains

Research by the New York Times and ProPublica shows that at least 10 percent of all county and state felony convictions involve drug charges. Of those, 90 percent involve plea deals and prosecutors in almost every jurisdiction accept guilty pleas based solely on the field tests.

Meanwhile, labs rarely notify police of false positives. Chronic staffing shortages cause many of the lab tests to be delayed by weeks or months. And recent improprieties in labs in Massachusetts and New Jersey have caused agencies to throw out tens of thousands of drugs cases.

If you or a loved one is arrested and charged with drug possession and a field drug test was used to determine the charge, you should contact a qualified, experienced criminal defense attorney to help you determine the best course of action.

No Comments

Leave a comment
Comment Information
  • Rated by Super Lawyers | J. Guthrie True |
  • Rated by Super Lawyers | Rising Stars | Whitney True Lawson |
  • Rated by Super Lawyers | Rising Stars |  Philip Lawson |
  • Distinguished AV | LexisNexis | Martindale-Hubbell | Peer Review Rated | For Ethical Standards and Legal Ability
  • American College of Trial Lawyers
  • Kentucky Bar Association | 1871
  • National Association of Criminal Defense Lawyers
  • American Board of Criminal Lawyers
  • Listed in Best Lawyers | The World's Premier Guide
  • Super Lawyers
Email Us For A Response

Ask Us Your Questions

Bold labels are required.

Contact Information

The use of the Internet or this form for communication with the firm or any individual member of the firm does not establish an attorney-client relationship. Confidential or time-sensitive information should not be sent through this form.


Privacy Policy

To learn more about working with us, call 502-783-7662 for a free consultation today.

Office Location:

True Guarnieri Ayer, LLP
124 Clinton St
Frankfort, KY 40601

Phone: 502-783-7662
Fax: 502-605-9901
Frankfort Law Office Map

Office Number: