The inherently dangerous nature of attack-trained police K-9s

While valuable to police work, these animals can pose a real danger to innocent bystanders, or lead to claims of excessive force when ordered to bite-and-hold a suspect

Richard Polsky, Ph.D.
2018 July

Approximately 4.5 million people are bitten by dogs each year in the United States. The literature contains a vast amount of information about costs associated with dog bite injury, hospitalizations, emergency room visits, breed of dog, characteristics of dog bite victims and other epidemiological statistics. Nonetheless, little is known about the frequency of dog bites inflicted on people by police dogs. The costs to municipalities to settle police dog bite claims are considerable, however.

A story published by in the Seattle Times in March 2013 reported on this issue. For example, over $1 million in damages was paid to 17 plaintiffs in western Washington state during a five-year period. It is likely that thousands of
people in the United States are attacked annually by police canines based on these statistics.

Another example of the high cost to municipalities for police dog bite claims comes from an incident that happened in Hayward, California in May 2011. The event began when police used their German Shepherd to search for the perpetrator of a robbery at a 7-Eleven store. The dog led police to an 8-foot wall abutting a trailer park. The handler lifted the dog over the wall. He then commanded the dog to continue the search, and shortly after that, the dog found a man sleeping under a bush. The dog viciously attacked the man. The dog’s handler had difficulty stopping the attack. The police immediately realized that this person was not the suspect they were seeking. The man died two months later from complications resulting from the incident. Records showed the dog had made previous mistakes, similar to what happened in this incident. This case settled for $1.5 million.

This article adds to the scant literature about the character and behavioral tendencies of the attack-trained police K-9. The purpose of this article is twofold. First, to explain why attack-trained police canines are inherently dangerous. Second, to identify the kind of information plaintiff attorneys needs to collect to prevail in lawsuits brought against the police because of a canine mauling.


The vast majority of dogs used by police for suspect apprehension are German Shepherds and Belgian Malinoises. The dogs are derived from lineages bred for protection and heightened aggressive reactivity. They are purchased in Europe by privately owned businesses in the United States (usually a training facility). At the time of purchase, the American buyer evaluates the temperament of the dog to ensure the dog will be a suitable candidate for police work. For example, as a narcotic detection dog or as a dog used to help in the apprehension of criminal suspects. The dog is then purchased (for about $8,000 - $10,000) and transported back to the United States for subsequent sale to the police.

The police department assigns the dog to a designated dog handler. The handler assumes full responsibility for the dog. For example, the newly adopted “canine partner” lives in the home of the handler. The training of the dog continues with the handler. Frequently the dog is trained as a “multitasker”; that is, trained for different jobs such as drug and bomb detection and suspect apprehension. The handler is required to keep records of all activities undertaken with the dog. The handler aims to have his canine partner certified for police work.

Dogs used for suspect apprehension are Schutzhund trained. Schutzhund is German for protection dog. There are three main components to Schutzhund training: obedience, searching, and protection. Schutzhund methods teach the dog to viciously bite, shake and hold the arm or leg of an “agitator.” The agitator wears heavy padding for protection.

Schutzhund methods also teach the K-9 to alert its handler (e.g., tail wagging, barking) after finding a suspect during a search. The K-9 then bites the suspect or waits for a command from the handler before starting an apprehension. The dog’s bite rate is a remarkable statistic. It refers to how often the dog bites a suspect. Not all apprehensions necessitate or involve bites from the dog. High bite rates indicate that the dog has a short latency to attack and a low threshold for biting. This is suggestive of a dog that is difficult to control.

Police departments have written policies and procedures. There are rules about deploying the K-9 to apprehend a suspect. For example, the handler must announce the presence of the dog to civilians, and that the dog will be released unless surrender is forthcoming from the suspect. The handler must follow department policy regarding whether the circumstances warranted using a K-9 to bite and apprehend a suspect. Was a force like this necessary? This topic is outside the scope of this article, however. I refer the reader to the many California appellate rulings on the use of force by police canines (e.g., Grant v. City of Los Angeles (1994); Quintanilla v. City of Downey, (1996); Vera Cruz v. City of Escondido, (1998).)

An animal behavior perspective on police dog behavior

Animal behavior is a scientific discipline which studies observable patterns of behavior. Animal behavior science aims to understand how patterns of behavior are affected by an animal’s genotype, environmental circumstances, contextual variables and the experiences of the animal. Analysis of the causation and motivation of behavioral patterns are made using the principals from the fields of learning, genetics, physiology, and neurobiology. Most major universities offer advanced degrees and training in the science of animal behavior.

The principles and mechanisms which govern the behavior and motivation of the attack-trained police K-9 are no different from those which govern all domestic dogs. These principles can be applied to the police K-9 much in the same way as they would for a Rottweiler, Labrador, Yorkshire Terrier or for that matter any other mammal.

Animal behavior analysis focuses on “why” questions about behavior. For example, why are police dogs inherently dangerous? Why do police dogs attack innocent bystanders? Why are police dogs unpredictable? Why are police dogs difficult to control? In contrast, the police dog handler asks “how” questions about police dog behavior. That is, how to teach a police K-9 to bite and hold, how to detect narcotics, how to follow a scent trail, and how to start and stop the attack on command, etc.

One can easily understand why attack-trained police K-9s are dangerous using an animal behavior perspective. Namely, these are carefully chosen individuals from breeding lines developed to produce dogs with innate aggressive tendencies. Subsequently, training techniques are used to raise the dog’s arousal and enhance its inherent aggressive tendencies. A highly aroused aggressive dog has a short latency to attack and less inhibition to attack, which makes the dog prone to committing behavioral mistakes. Police dogs with relatively little attack inhibition and short latencies to attack are difficult to control. In sum, the genotype of the dog and its experience create a dog eager to attack. The act of attacking in itself is a reward for the dog.

Seven reasons why attack-trained police dogs are inherently dangerous

  1. Attack-trained police dogs have innate tendencies for aggression, and training enhances these tendencies

The Belgian Malinois and German Shepherd are dogs that have been developed explicitly for protection. For example, German Shepherds are the prototypical guard dog, and the Belgian Malinois was the breed used in the capture of Osama bin Laden. Moreover, as previously mentioned, those German Shepherds and Belgian Malinois selected for police work are derived from lineages selectively bred for protection and heightened aggressive reactivity. In fact, individuals that do not show strong, aggressive propensities at the time of sale are usually not chosen. Finally, the dog’s inborn aggressive tendencies are enhanced and further developed through hundreds of training sessions and with the use of shock collars. In short, genetics and experience produce an exceptionally aggressive dog.

  1. Attack-trained police K-9s inflict severe dog bite injuries

When an attack-trained police dog attacks a person, the dog bite injuries inflicted to the victim are usually severe. Research has shown that when compared with the bite injuries inflicted to a person from a similar size domestic dog, wounds inflicted on people by an attack-trained police dog require greater medical intervention.

Peter C. Meade addressed this issue in a 2006 paper entitled “Police and Domestic Dog Bite Injuries: What are the Differences? What are the Implications for Police Dog Use?” This study analyzed medical information related to dog bite injury inflicted on people by police dogs.

The study compared the medical intervention needed for bite injuries inflicted by a police dog with bite injuries caused by a domestic dog. An inner-city public hospital in Los Angeles, the King-Drew Medical Center, was the source of the data. Results focused on the difference in the severity of injury between 595 victims of police dog attack and the injuries of 1109 people attacked by a dog not used for police work.

Meade concluded that the severity of a bite from a police dog was more significant than the severity of a bite from a non-police dog. Police dog bite victims were bitten multiple times and more often bitten in the head, neck, chest, and flank. Also, police dog bites more often resulted in hospitalization, operations, and invasive diagnostic tests. Meade argues that the types of dogs selected to be police dogs, as well as their specialized training, were the cause for these differences.

  1. Attack-trained police dogs are unpredictable

The vicious, unprovoked attack on a four-year-old boy in Hesperia, California, in February 2015 shows the unpredictable and inherently dangerous nature of the attack-trained K-9. The context in which this incident happened was somewhat shocking.

In this incident, a six-year-old Belgian Malinois, named Jango, nearly killed the son of the dog’s handler (a police officer with the Rialto Police Department). Jango was born and initially trained in Holland before being brought to the United States. The fact pattern of the incident was as follows: The father returned home after being absent for about two days, released Jango from his kennel and then placed Jango in the backyard to relieve himself. After releasing Jango into the yard, he went to shower, leaving his four-year-old son unattended downstairs.

The mother was not home because she had gone shopping. The boy gained access to the backyard by opening the sliding glass door. Speculation is that he went looking for his mother. Jango attacked the child. His screams alerted the neighbors. The neighbors arrived, but they had to knock down the backyard fence to gain access to the dog. Jango had the leg of the boy in its mouth and was shaking it. One of the neighbors started kicking the dog, but this did not stop Jango. One neighbor pried open the mouth of Jango, and he released the boy. The father came to the scene and placed Jango back in his kennel. The boy was airlifted to a local hospital. His leg was amputated just below the knee because of severe vascular damage.

  1. Attack-trained police dogs act impulsively

Attack-trained police dogs possess an eagerness to attack. This eagerness causes the dog to act impulsively. Impulsivity lowers the dog’s attack latency and its threshold for an attack. Moreover, it interferes with the dog’s decision-making abilities and its ability to comply with vocal commands from the handler. Impulsivity is a well-recognized psychological trait associated with attacks on people in many different breeds of dog.

  1. Attack-trained police dogs attack the wrong people

There are many documented accounts in which attack-trained police dogs have viciously attacked the wrong people. For example, in a study presented at a conference on animal behavior, I showed data on 30 instances involving attacks on innocent bystanders. I found that in all cases the police K-9 was in the midst of searching for a suspect. In one example, the dog attacked a senior on a swing in the yard of a convalescent home. And in another incident, a dog attacked a taco vendor on a city street in Denver.

The reason innocent bystanders are attacked by police dogs is understood best through animal behavior analysis. Namely, when these dogs are in the midst of searching for a suspect, they are highly motivated to find a person to attack. Usually, the dog finds the suspect, but all too often the wrong person is attacked. These dogs are on a mission and are goal driven. The act of searching for the suspect and the anticipation of biting a suspect is a reward in itself. Hence, it is not surprising that at times these dogs make mistakes and attack a person other than the suspect they were seeking.

  1. Often the attack of an attack-trained police dog cannot be quickly stopped

The attack-trained police dog frequently will not stop its attack despite being told to do so by the handler. Consequently, the dog excessively bites the victim. The dog’s failure to stop its attack is contrary to its training. That is, cease an attack on verbal command. A handler may choose to terminate the attack by forcibly pulling the dog from the suspect. However, removing the dog may be difficult and if used, the dog’s teeth will likely rip through the suspect’s flesh, causing additional damage.

Attack-trained police canines are taught to apprehend suspects with the “bite and hold” technique. The use of this technique is controversial because of the severity of injury inflicted on a person by the dog. The method calls for the dog to bite and shake the arm or leg of a suspect and then hold the suspect with its mouth for as long as needed until called-off by the handler. This technique usually results in severe injury because, as mentioned above, the dog will not release when commanded to do so or because the dog regrips and then continues to bite. Excessively biting or failure to release on command are examples of the behavioral mistakes these highly aroused dogs often make.

A lawsuit was made against the police in Pittsburg, California alleging excessive force. A female Belgian Malinois named Xena viciously bit the plaintiff in this May 2011 incident. The police alleged that the suspect resisted arrest. They attempted to subdue the suspect with a Taser gun, but this was ineffective. Therefore, the police deployed Xena to assist in the apprehension. Xena attacked the plaintiff and continued to bite the plaintiff for about 30-40 seconds. The police did not dispute this duration but alleged that the plaintiff’s kicking behavior was the impetus which caused Xena to bite the plaintiff repeatedly. Throughout Xena’s attack on the plaintiff, the handler could be heard telling his dog “good girl, good girl.” The attack ended when Xena’s handler pulled her away from the plaintiff.

Did Xena excessively bite the plaintiff? The defense argued that the plaintiff’s kicking prevented Xena from holding the plaintiff. This argument made no sense. For example, pit bulls and mastiffs can easily bite and hold a person, even without specific bite-and-hold training. Another disturbing fact was the police version of events. Namely, the plaintiff was face down on the ground while he was kicking Xena. One wonders how the plaintiff’s kicking could deter a dog supposedly proficient in the bite-and-hold technique.

There are two plausible reasons why the attack lasted as long as it did: (1) Either the handler intentionally let Xena continue to attack the plaintiff for the duration of time beyond what was needed to make a successful apprehension. Note that the police may have formed a dislike for the plaintiff due to previous encounters; or (2) the handler lost control of Xena after the attack started because of the dog’s highly aroused aggressive state. If this is the case, then the handler lost control over his canine partner.

This example suggests that attack-trained police canines may excessively bite when they attempt to use the bite-and-hold technique. This excessive biting may stem from the dog’s inexperience in using the bite-and-hold in field situations (discovery showed that this was the case for Xena), or the dog’s eagerness to attack, the dog’s heightened level of arousal, and the dog’s desire to “get the job done.” The case settled for $145,000 at the insistence of the plaintiff; it likely would have brought far more at trial.

  1. Attack-trained police dogs are repeat offenders

Police departments may choose to keep a K-9 in service despite their knowledge that the dog has a history of inappropriately biting people. An example is an incident that happened in Coconut Creek, Florida in February 2015. The handler of a four-year-old Belgian Malinois named Renzo met with several other police officers in a parking lot at Dunkin’ Donuts. The handler left Renzo in the squad car. One of the officers approached the car to pet Renzo, and this caused Renzo to lunge at the officer. Renzo then leaped out of the vehicle and viciously attacked a donut shop worker present in the vicinity.

This was not the first mistake committed by Renzo. Renzo attacked another person several months earlier. In this instance, Renzo was searching for a suspect, and his handler tripped. Renzo then viciously attack a nearby officer, inflicting multiple puncture wounds on the officer’s leg.

Police departments are often reluctant to remove a dog from service. The high cost of buying police dogs and the efforts already invested in training and caring for the dog are the likely reasons why repeat offenders do not have early retirements.

Discovery to win a lawsuit against the police

Proving a claim of excessive force depends in part on establishing the handler did not have control over his dog. If the dog was not under control, then it becomes easier for a jury to believe the attack by the dog was excessive or that it was not warranted.

You stand a greater chance of winning a lawsuit against the police by (a) Finding evidence which indicates that the dog was difficult to control or out of control at the time of the incident, and (b) Buttressing these findings with explanations about why attack-trained police K-9s are inherently dangerous.

The collection of discovery should proceed as follows:

  1. Depose the handler, his supervisor and anyone familiar with the dog.

First, determine if any medical or behavioral problems existed before the incident (e.g., excessive barking, thyroid levels, skin problems, arthritis, separation anxiety, etc.), or if the dog required remedial work for certification. Moreover, find out about previous aggressive displays and the circumstances when the dog growled, snarled, chased, barked, lunged at, jumped on, or bit a fellow officer, an innocent bystander, or any human or dog.

Second, ask questions about:

  • The background of the handler and when he started working with this dog;
  • Previous K-9s the handler may have worked with;
  • Any instance in which the K-9 was removed or retired from service;
  • Educational activities and continuing education courses;
  • The relationships the dog had with the handler and others when not on duty;
  • All training activities inclusive of their frequency, when and where training took place, with whom it took place and if any videos are available for training sessions;
  • The commands taught to the dog. Why the commands used?
  • Nature of the supervision the handler received from others, including the immediate supervisor;
  • How the incident happened including events immediately before and those leading up to the episode. Work backward in time for at least 24 hours;
  • A typical day in the life of the dog;
  • Previous deployments of the dog and the usual protocol followed during these deployments.
  1. Subpoena all records about the dog

These include the dog’s veterinary records, proof of certification, records of purchase and lineage, records of all training sessions and logs of all deployments. Training records must be examined in great detail to determine how the dog was taught to apprehend (e.g., bark and hold versus bite and hold), the frequency of training, and the “error rate” of the dog. The error rate is the percentage of time the dog fails in a training exercise (e.g., obedience). Another important metric is the dog’s bite rate. Bite rate is the number of apprehensions with bites divided by the total number of apprehensions. High bite rates indicate a difficult-to-control dog or a dog that has poor bite inhibition.

  1. Obtain documentation about policies and procedures

These records might be of significance because a police K-9 is prone to making mistakes if the handler failed to follow the protocol concerning the training or management of the dog.

  1. Conduct a behavioral examination of the dog

This assumes the dog is still in service. An examination shows how much verbal control the handler has over the dog for the various activities associated with suspect apprehension. For example, does the dog comply with obedience commands; does the handler have good verbal control over the dog; and how much difficulty does the handler have in stopping an attack on an agitator?

Summary and conclusions

One should not disregard the benefits to police work of an attack-trained police K-9. These dogs are a tremendous help in the detection and deterrence of crime. Nonetheless, the use of these dogs carries substantial risk. These dogs frequently attack the wrong people; they are impulsive and unpredictable, they attack people out of context; and once they start an attack, they will not readily stop. These dogs are not the robotic machines the police would like others to believe. They make mistakes. A dog of this nature cannot be fully trusted. Attack-trained police dogs have an eagerness to attack. They welcome the opportunity to attack. From the dog’s perspective, it has a job to get done.

No matter how well trained the dog is or how experienced the handler, considerable risk always exists in that the handler will lose control of the dog, thereby making it foreseeable that handler will be unable to quickly stop an attack or prevent the dog from attacking the wrong person or attacking in inappropriate contexts. These risks must be minimized to ensure the safety of the public and the suspects these dogs are trained to attack.

Further reading

Hickey, E, Hoffman, P., To bite or not to bite: Canine apprehensions in a large, suburban police department. Journal of Criminal Justice. 2003, 31, 147-154.

Meade, P., Police and domestic dog bite injuries: What are the differences? What are the implications for police dog use? Injury, 2006, 37, 395-401.

Mesloh, C., Barks or Bites? The Impact of Training on Police Canine Force Outcomes. Police Practice and Research, 2006, 7, 323-335.

Richard Polsky, Ph.D.

Richard Polsky, Ph.D. is the President of Animal Behavior Counseling Services, Inc.  Dr. Polsky is an academically trained animal behaviorist with over 30 years’ experience working with dogs in applied settings. He is well-published in peer-reviewed journals and has extensive experience of testifying in court as a dog bite expert. Dr. Polsky has helped hundreds of attorneys gain favorable outcomes for their clients. More information about his background, qualifications, and resources for attorneys handling dog bite cases can be found at Email

The inherently dangerous nature of attack-trained police K-9s

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