Why Police Shoot Someone Holding a Knife

To begin this article, the video below shows the line of duty death of Las Cruces Police Department Officer Jonah Hernandez.

**Warning:** The footage is extremely graphic. It is included not for shock value, but because it demonstrates the reality of how quickly a knife attack can become deadly. Within seconds, what appears to be a routine encounter turns into a fatal assault, highlighting why officers are trained to recognize edged weapons as an immediate deadly threat.

https://www.youtube.com/watch?v=YU4VJyBAg7E

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Every time a police shooting involving a knife makes national headlines, the same questions immediately appear online.

"Why didn't they just shoot the knife out of his hand?"

"Why didn't they use a Taser?"

"It's just a knife."

These questions are understandable. To someone watching a short cellphone clip or body camera video, it can seem like there should have been another option. The reality, however, is that a knife is one of the most dangerous weapons an officer can face, particularly at close distances.

Understanding why officers sometimes use deadly force against someone armed with a knife requires looking at the threat from a practical standpoint rather than an emotional one.

A Knife Is Deadly Force

A common misconception is that a knife is somehow a "less deadly" weapon because it is not a firearm.

That simply is not true.

A fixed blade knife, folding knife, kitchen knife, machete, or any other edged weapon is fully capable of causing death or catastrophic injury within seconds. Deep cuts to the neck, chest, abdomen, or major arteries can rapidly become fatal. Even a single stab wound can permanently disable or kill someone.

Because of this, American law enforcement agencies universally recognize an edged weapon as a deadly weapon. Courts have repeatedly upheld that officers do not have to wait until they are stabbed before defending themselves or another person.

The legal standard is not whether the suspect actually used the knife.

The question is whether a reasonable officer would believe there was an imminent threat of death or serious bodily injury.

Distance Changes Everything

One of the biggest mistakes people make is assuming distance equals safety.

It does not.

A person standing twenty or thirty feet away with a knife can close that distance far faster than most people realize.

Law enforcement training often references what's commonly called the "21-Foot Rule." While many people incorrectly treat it as an absolute rule, it is better understood as a training concept. It demonstrates that an attacker armed with an edged weapon can often cover approximately 21 feet before an officer can reliably recognize the threat, draw a holstered firearm, and accurately stop the attack.

The exact distance varies depending on countless factors, including reaction time, obstacles, footwear, physical ability, and whether the officer's weapon is already drawn.

The lesson is simple.

Close-quarter encounters with a knife are extremely dangerous because human reaction time has limits.

Why Not Just Use a Taser?

Another common question is why officers do not simply deploy a Taser.

Tasers are an excellent less-lethal tool, but they are not guaranteed to work.

Heavy clothing can interfere with the probes. One probe may miss. The wires may break. The subject may pull the probes out. The device may fail to establish neuromuscular incapacitation. Sometimes a subject simply continues fighting despite being exposed.

Because Tasers are less-lethal tools, officers generally should not rely on one when a deadly threat is already unfolding unless time, distance, and circumstances make it reasonably safe to do so.

If someone armed with a knife is already charging or rapidly advancing within close range, there may not be enough time for a failed Taser deployment followed by another attempt before someone is seriously injured.

Why Officers Don't Shoot the Hand or Leg

Hollywood has created unrealistic expectations about police shootings.

Officers are trained to stop the threat, not to perform precision marksmanship under extreme stress.

Hands and legs are constantly moving, relatively small targets. Attempting to intentionally wound someone greatly increases the likelihood of missing entirely and endangering innocent people nearby.

Additionally, shooting someone in the leg is not a less-lethal option. Bullets striking the femoral artery can quickly become fatal, and leg wounds do not reliably stop an attack.

For that reason, officers are trained to aim for the largest available target in order to stop an imminent deadly threat as quickly as possible.

Deadly Force Is About Imminent Threats

One of the biggest misunderstandings surrounding police use of force is the belief that officers can only shoot after someone has already attacked.

That is not how the law works.

If an objectively reasonable officer believes a person armed with a deadly weapon is about to cause death or serious bodily injury, deadly force may be legally justified before the first stab occurs.

Waiting until an officer, victim, or bystander is already being stabbed defeats the purpose of protecting life.

Every situation is different. Factors such as distance, barriers, available cover, the subject's actions, available backup, nearby civilians, and opportunities to de-escalate all influence an officer's decision.

No single factor automatically justifies deadly force.

Instead, officers must evaluate the totality of the circumstances in real time, often within only a few seconds.

The Cory Ruiz Shooting

One recent example generating significant public discussion is the officer-involved shooting involving Cory Ruiz in Madison, Wisconsin.

At the time of writing, the investigation remains ongoing, and many important facts have not yet been officially released. As additional evidence, witness statements, and investigative findings become available, the overall circumstances may become clearer. Because of that, Police Breakdown will publish a separate article dedicated to analyzing the complete incident once the investigation provides a more complete factual picture.

One fact that has been widely observed from the currently available video is that Ruiz was armed with what appears to be a fixed-blade knife during the encounter.

From an officer safety perspective, that fact alone is extremely significant.

A fixed-blade knife is a deadly weapon capable of inflicting fatal injuries within moments, particularly when an encounter occurs at close range. If an armed subject rapidly closes distance or presents an imminent threat to officers or others, deadly force may be legally justified under those circumstances. The presence of a knife should never be dismissed simply because it is not a firearm.

Whether deadly force was legally justified in the Ruiz incident ultimately depends on the totality of the facts, including the officers' observations, Ruiz's actions, distance, movement, available alternatives, and what a reasonable officer perceived at that moment. Those are questions that deserve careful analysis based on the completed investigation rather than assumptions or incomplete video clips.

Knife encounters are among the most dangerous situations officers face.

Unlike firearms, which create danger primarily at distance, knives become exceptionally lethal once someone gets within striking range. Officers are trained to recognize that reality because hesitation of even a second can result in catastrophic injuries to officers, victims, or innocent bystanders.

Every police use of force deserves careful scrutiny. That scrutiny, however, should be based on facts, established legal standards, and an understanding of how rapidly violent encounters unfold, not on television portrayals or assumptions made from a few seconds of video.

Understanding why officers sometimes use deadly force against someone armed with a knife does not require supporting every police shooting. It simply requires recognizing that an edged weapon is a deadly weapon, and that waiting until someone has already been stabbed is often waiting too long.