Lyons Snyder & Collin. Trial Attorneys.


Are drug-detection dogs reliable?

By Philip M. Snyder

As a criminal defense attorney in Fort Lauderdale, FL, I occasionally review drug cases where police officers employ the use of a drug-detection dog to alert to the exterior of a suspect’s vehicle to provide them with probable cause to conduct a warrantless search of the interior of the suspect’s vehicle (i.e. canine sniff.)  Until recently, the Courts in Florida were split as to how much evidence the State needed to provide at a Motion to Suppress to show that the drug-detection dog’s alert sufficiently provided the police with probable cause to perform a warrantless search.  As a result of the recent ruling in Harris v. State, 2011 WL 1496470 (Fla. 2011), defense attorneys throughout Florida can rejoice that the Florida Supreme Court has finally issued a ruling on how the Court should evaluate the reliability of a drug-detection dog and its handler and what evidence the State needed to provide at a Motion to Suppress.  Of note, Harris is a significant win for defense attorneys as it significantly increases the scrutiny attached to drug-detection dogs and their handlers and firmly places the burden on the State to present the proper evidence at a Motion to Suppress.

The crucial factor is the reliability of the drug-detection dog

Whether a dog’s alert provides probable cause for a search hinges on the dog’s reliability as a detector of illegal substances within the vehicle.  As a result of Harris, and in a departure from previous District Court rulings, evidence that a drug-detection dog has been trained and certified to detect narcotics, standing alone, is not sufficient to establish the dog’s reliability for purposes of determining probable cause. Now, the police officer’s blind assertion that his/her dog is properly “trained” and “certified” is just the beginning of the Court’s determination into whether the police had probable cause to search.  For the State to establish that the police had a reasonable basis to believe that a drug-detection dog was reliable in order to establish probable cause through a canine sniff, the State must present all records and evidence that is necessary to allow the trial court to evaluate the reliability of the dog, including:

1.     The drug-detection dog’s training and certification records;

2.     An explanation of the meaning of the particular training and certification of that particular dog;

3.     Field performance records;  and

4.     Evidence concerning the experience and training of the police officer handling the drug-detection dog, as well as any other objective evidence known to the police officer about the dog’s reliability in being able to detect the presence of illegal substances within the vehicle.

Importantly, Harris reaffirms that the State, and not the defense, has the burden of

presenting evidence of the dog’s reliability at a Motion to Suppress.  Pre-Harris, some Courts required the defendant to introduce the dog’s field performance records, or other evidence such as expert testimony, to rebut the handler’s assertion that his/her drug-detection dog was properly “trained” and “certified.”   Now the State must present evidence at a Motion to Suppress documenting:

  1. The dog’s exact training;
  2. The police officer’s criteria for selecting his/her drug-detection dog;
  3. The standards the dog was required to meet to successfully complete the training program; and
  4. The “track record” of the dog in the field, with an emphasis on the number of mistakes the dog has made.  

The Harris opinion also discussed, at length, the potential for dogs to issue “false alerts”, the potential for the dog’s handler to make errors, subconscious (and conscious) cues from handlers, and the possibility of the dog alerting to residual odor (i.e. when a dog signals an alert where drugs were formally, and not currently, present).   

A “false alert” is an alert by the dog in the absence of the substance it is trained to detect (i.e. an alert to baby powder instead of cocaine.)   False alerts may lead to the search of a person who is innocent of any wrongdoings.  False alert rates vary significantly among certified detection dogs.  

The Harris Court opined that false alerts may indicate that a drug-detection dog is not well-trained or cannot differentiate residual odors from actual odors.  Evidence of a dog’s performance history – and the significance of any incidents where the dog alerted without contraband being found – is part of the Court’s (complete) evaluation of the dog’s reliability under the totality of the circumstances analysis.    Information that merely tallies successes does not provide a complete picture.  Well-presented data should include the numbers of failures, if any, and the conditions under which they occurred.”


Although Harris is a significant case, I suspect that law enforcement will still only “conservatively” document when their drug-detection dog makes a “mistake” in the field or in training.   Cases such as Harris, are clearly steps in the right direction, but skilled criminal defense attorneys are necessary to properly cross-examine obstinate police officers concerning the reliability of their drug-detection dogs and challenge the Court to follow to the law. Although Harris provides specific guidelines, the ultimate determination of the drug-detection dog’s reliability still resides with the trial court.  Harris does not afford the trial with a bright-line rule in which to follow.  As such, if you or a family member has been arrested in a case where drugs were found after a drug-detection dog alerted to your car or person, it is important to contact an experienced criminal defense attorney familiar with canine sniff cases.

Criminal defense lawyer Philip M. Snyder is a founding partner of Lyons, Snyder & Collin, P.A. in Fort Lauderdale, Florida.    Fort Lauderdale criminal defense attorney Philip M. Snyder handles all criminal defense matters including, drug cases, trafficking cases, domestic violence, and assault and battery.   The Fort Lauderdale criminal defense law firm of Lyons, Snyder & Collin, P.A. is located at 312 Southeast 17th Street, Third Floor, Fort Lauderdale, Florida 33316.  Telephone: 954.462.8035.