Missouri Assault Laws and Penalties

Felony and misdemeanor assault in Missouri carry serious penalties.

By , Attorney · UNLV William S. Boyd School of Law
Updated by Rebecca Pirius, Attorney · Mitchell Hamline School of Law
Updated 11/08/2022

Missouri divides its assault offenses into four degrees. First-degree assault is the most serious and fourth-degree the least. Assault crimes range from misdemeanors to class A felonies. Read on to learn how Missouri defines and penalizes the various degrees of assault.

What Is Assault in Missouri?

In Missouri, a person can commit assault by:

  • inflicting, or attempting to inflict, physical injury on another
  • touching someone in an offensive or provocative manner, or
  • placing another in fear of imminent harm.

The state divides its assault offense by severity in terms of the offender's conduct, the level or risk of harm, and the victim involved. Below are definitions associated with the different assault crimes. To skip down to the penalties, click here.

Definitions of Knowing, Reckless, and Criminal Negligence

In assault crimes, a defendant who acts knowingly will generally be punished more severely than if the same act had been done recklessly or negligently.

Knowing. A person acts knowingly when they are aware that their conduct is practically certain to bring about a particular result. For example, aiming a cocked and loaded handgun at another person, and then pulling the trigger, is practically certain to cause injury to the other person.

Reckless. A reckless act is one that is committed, not necessarily with intent to harm another, but without regard for the outcome. A person who shoots a gun into the air at a festival, perhaps, didn't intend to harm anyone, but their actions were reckless and could easily cause harm.

Criminal negligence. A person acts with criminal negligence by failing to be aware of a substantial and unjustifiable risk. Pushing through a crowded room near a set of steep stairs and knocking someone down those stairs could be considered criminal negligence.

Definitions of Deadly Weapons and Dangerous Instruments

An assault involving a deadly weapon or dangerous instrument increases the risk of harm to a victim.

Deadly weapon. A deadly weapon is any firearm (loaded or unloaded), or any weapon from which a shot, readily capable of producing death or serious physical injury, may be discharged. Switchblade knives, daggers, billy clubs, blackjacks, and metal knuckles are also considered deadly weapons.

Dangerous instrument. A dangerous instrument is any instrument, article, or substance that, under the circumstances in which it is used, is readily capable of causing death or other serious physical injuries. A rope used to strangle someone, a metal pipe used to strike someone, and a vehicle used to intentionally strike a pedestrian are all dangerous instruments because of the manner in which they were used.

Definitions of Serious Physical Injury and Physical Injury

The greater the resulting or attempted harm is, the more serious the penalties for assault will be.

Serious physical injury means physical injury that creates a substantial risk of death or that causes serious disfigurement or protracted loss or impairment of the function of any part of the body. Common examples include gunshot wounds, knife wounds, and beatings that result in cracked ribs, punctured lungs, or broken bones.

Physical injury refers to minor injuries to the human body, including scrapes, lacerations, and bruises.

Definition of Special Victims

Missouri punishes assault more harshly when it's committed against a "special victim," as defined in law. Special victims include elderly, disabled, and vulnerable individuals. The law also protects the following special victims who work in vulnerable positions if the assault took place while they were performing their duties or as a direct result of those duties:

  • law enforcement officers
  • emergency personnel (firefighters, ER staff, EMTs)
  • corrections officers (parole, probation, jailors), and
  • utility, highway, and mass transit workers.

(Assaults against family and household members are punished as domestic assault in the first- through fourth-degrees. Check out our article for more information.)

What Is the Penalty for First-Degree Assault in Missouri?

A person is guilty of 1st-degree assault if they:

  • attempt to kill another person, or
  • knowingly cause or attempt to cause another person serious physical injury.

Penalties; first degree. If a first-degree assault results in serious physical injury to the victim, the crime is a class A felony, which is punishable by 10 to 30 years (or even life) in prison. The same penalty applies if the defendant committed the offense against a special victim. In all other cases, the crime is a class B felony, punishable by 5 to 15 years in prison.

Sudden passion; second degree. A defendant who commits the above offense but acted out of a sudden influence of passion, rather than knowingly or intentionally, commits second-degree assault (rather than first-degree). But it's on the defendant to prove it. To do so, the defendant must show that their heightened emotional state and out-of-control actions were caused by a sudden, unexpected event that was provoked by another.

What Is the Penalty for Second-Degree Assault in Missouri?

A person is guilty of 2nd-degree assault if they:

  • attempt to kill another person or cause or attempt to cause serious physical injury to another person while "under the influence of sudden passion arising out of adequate cause" (see explanation above)
  • attempt to cause or knowingly cause physical injury to another with a deadly weapon or dangerous instrument
  • recklessly cause serious physical injury to another, or
  • recklessly cause physical injury to another by discharging a firearm.

Assault in the second degree is a class D felony, punishable by up to seven years in prison and a $10,000 fine. If the offense involved a special victim, the defendant faces a class B felony and 5 to 15 years in prison.

What Is the Penalty for Third-Degree Assault in Missouri?

A person is guilty of 3rd-degree assault if they knowingly cause physical injury to another.

The crime is a class D felony if committed against a special victim and punishable by up to seven years in prison, a fine up to $10,000, or both. All other offenses are Class E felonies, which carry a possible sentence of four years in prison and a $10,000 fine.

What Is the Penalty for Fourth-Degree Assault in Missouri?

A person is guilty of 4th-degree or misdemeanor assault if they:

  • attempt or recklessly cause physical injury, pain, or illness to another
  • negligently causes physical injury to another by means of a firearm
  • recklessly engage in conduct that creates a substantial risk of death or serious physical injury to another person, or
  • knowingly attempt or engage in physical contact that's offensive or provocative and the victim is a person with a disability.

These offenses carry class A misdemeanor penalties of up to one year in jail and a $2,000 fine.

It's also 4th-degree or misdemeanor assault to:

  • purposely causing another to fear imminent physical injury, or
  • knowingly engages in offensive or provocative contact with a person.

A person who commits one of these offenses faces a class C misdemeanor, punishable by up to 15 days in jail, a fine up to $750, or both. However, the penalty increases to a class A misdemeanor (with the penalties noted above) if the offense involves a special victim.

Missouri's Sentencing Enhancements for Prior and Persistent Assault Offenders

Any offender with one or more prior "assault offenses" faces the possibility of a stiffer sentence in terms of length and disposition. For these sentencing enhancements, assault offenses are defined broadly to include first- through fourth-degree assault and domestic assault, murder, and manslaughter.

Judges must sentence "prior assault offenders"—those with one prior in five years—to the next higher felony class if they were found guilty of a class B, C, or D felony. For "persistent assault offenders" having two or more priors in 10 years, the sentence goes up two classes (except class B goes up to class A).

Neither prior nor persistent assault offenders qualify for suspended sentences. These offenders must also serve at least six months before becoming eligible for probation or parole.

Defenses to Assault Charges in Missouri

Common defenses to assault charges include "it wasn't me" and self-defense. A defendant arguing self-defense typically claims that they were not the aggressor—rather, they responded to a threat with a reasonable amount of force. Winning on either defense means the defendant must be acquitted.

Another defense strategy is to poke holes in the prosecutor's case. The defense attorney might argue, for example, that the prosecutor didn't prove that the injuries were substantial or that the defendant acted knowingly. If the prosecutor's case completely falls apart, the defendant may be acquitted. In other cases, the jury might find the defendant guilty of lower assault charges.

The Value of Good Representation

If you face criminal charges for a felony or misdemeanor assault, contact a criminal defense attorney. In addition to possibly spending time behind bars, any record of assault will make it difficult in the future to get a job, housing, or loan. A criminal defense lawyer can help explain the charges, protect your rights, and defend your case.

(Mo. Rev. Stat. §§ 565.002, 565.050, 565.052, 565.054, 565.056, 565.079 (2022).)

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