Missouri

Permit Eligibility

A concealed carry permit issued pursuant to subsection 7 of this section shall be issued by the sheriff or his or her designee of the county or city in which the applicant resides, if the applicant:

1. Is at least nineteen years of age, is a citizen or permanent resident of the United States and either:
   1. Has assumed residency in this state; or
   2. Is a member of the Armed Forces stationed in Missouri, or the spouse of such member of the military;
2. Is at least nineteen years of age, or is at least eighteen years of age and a member of the United States Armed Forces or honorably discharged from the United States Armed Forces, and is a citizen of the United States and either:
   1. Has assumed residency in this state;
   2. Is a member of the Armed Forces stationed in Missouri; or
   3. The spouse of such member of the military stationed in Missouri and nineteen years of age;
3. Has not pled guilty to or entered a plea of nolo contendere or been convicted of a crime punishable by imprisonment for a term exceeding one year under the laws of any state or of the United States other than a crime classified as a misdemeanor under the laws of any state and punishable by a term of imprisonment of two years or less that does not involve an explosive weapon, firearm, firearm silencer or gas gun;
4. Has not been convicted of, pled guilty to or entered a plea of nolo contendere to one or more misdemeanor offenses involving crimes of violence within a five-year period immediately preceding application for a concealed carry permit or if the applicant has not been convicted of two or more misdemeanor offenses involving driving while under the influence of intoxicating liquor or drugs or the possession or abuse of a controlled substance within a five-year period immediately preceding application for a concealed carry permit;
5. Is not a fugitive from justice or currently charged in an information or indictment with the commission of a crime punishable by imprisonment for a term exceeding one year under the laws of any state of the United States other than a crime classified as a misdemeanor under the laws of any state and punishable by a term of imprisonment of two years or less that does not involve an explosive weapon, firearm, firearm silencer, or gas gun;
6. Has not been discharged under dishonorable conditions from the United States Armed Forces;
7. Has not engaged in a pattern of behavior, documented in public or closed records, that causes the sheriff to have a reasonable belief that the applicant presents a danger to himself or others;
8. Is not adjudged mentally incompetent at the time of application or for five years prior to application, or has not been committed to a mental health facility, as defined in section 632.005, or a similar institution located in another state following a hearing at which the defendant was represented by counsel or a representative;
9. Submits a completed application for a permit as described in subsection 3 of this section;
10. Submits an affidavit attesting that the applicant complies with the concealed carry safety training requirement pursuant to subsections 1 and 2 of section 571.111;
11. Is not the respondent of a valid full order of protection which is still in effect;
12. Is not otherwise prohibited from possessing a firearm under section 571.070 or 18 U.S.C. Section 922(g).

Mo. Rev. Stat. § 571.101 (2)

Training Requirements

1. An applicant for a concealed carry permit shall demonstrate knowledge of firearms safety training. This requirement shall be fully satisfied if the applicant for a concealed carry permit:
   1. Submits a photocopy of a certificate of firearms safety training course completion, as defined in subsection 2 of this section, signed by a qualified firearms safety instructor as defined in subsection 6 of this section; or
   2. Submits a photocopy of a certificate that shows the applicant completed a firearms safety course given by or under the supervision of any state, county, municipal, or federal law enforcement agency; or
   3. Is a qualified firearms safety instructor as defined in subsection 6 of this section; or
   4. Submits proof that the applicant currently holds any type of valid peace officer license issued under the requirements of chapter 590; or
   5. Submits proof that the applicant is currently allowed to carry firearms in accordance with the certification requirements of section 217.710; or
   6. Submits proof that the applicant is currently certified as any class of corrections officer by the Missouri department of corrections and has passed at least one eight-hour firearms training course, approved by the director of the Missouri department of corrections under the authority granted to him or her, that includes instruction on the justifiable use of force as prescribed in chapter 563; or
   7. Submits a photocopy of a certificate of firearms safety training course completion that was issued on August 27, 2011, or earlier so long as the certificate met the requirements of subsection 2 of this section that were in effect on the date it was issued.
2. A certificate of firearms safety training course completion may be issued to any applicant by any qualified firearms safety instructor. On the certificate of course completion the qualified firearms safety instructor shall affirm that the individual receiving instruction has taken and passed a firearms safety course of at least eight hours in length taught by the instructor that included:
   1. Handgun safety in the classroom, at home, on the firing range and while carrying the firearm;
   2. A physical demonstration performed by the applicant that demonstrated his or her ability to safely load and unload either a revolver or a semiautomatic pistol and demonstrated his or her marksmanship with either firearm;
   3. The basic principles of marksmanship;
   4. Care and cleaning of concealable firearms;
   5. Safe storage of firearms at home;
   6. The requirements of this state for obtaining a concealed carry permit from the sheriff of the individual's county of residence;
   7. The laws relating to firearms as prescribed in this chapter;
   8. The laws relating to the justifiable use of force as prescribed in chapter 563;
   9. A live firing exercise of sufficient duration for each applicant to fire either a revolver or a semiautomatic pistol, from a standing position or its equivalent, a minimum of twenty rounds from the handgun at a distance of seven yards from a B-27 silhouette target or an equivalent target;
   10. A live-fire test administered to the applicant while the instructor was present of twenty rounds from either a revolver or a semiautomatic pistol from a standing position or its equivalent at a distance from a B-27 silhouette target, or an equivalent target, of seven yards.
3. A certificate of firearms safety training course completion may also be issued to an applicant who presents proof to a qualified firearms safety instructor that the applicant has passed a regular or online course on firearm safety conducted by an instructor certified by the National Rifle Association that is at least one hour in length and who also passes the requirements of subdivisions (1), (2), (6), (7), (8), (9), and (10) of subsection 2 of this section in a course, not restricted by a period of hours, that is taught by a qualified firearms safety instructor.
4. A qualified firearms safety instructor shall not give a grade of passing to an applicant for a concealed carry permit who:
   1. Does not follow the orders of the qualified firearms instructor or cognizant range officer; or
   2. Handles a firearm in a manner that, in the judgment of the qualified firearm safety instructor, poses a danger to the applicant or to others; or
   3. During the live-fire testing portion of the course fails to hit the silhouette portion of the targets with at least fifteen rounds.

Mo. Rev. Stat. § 571.111

Application ProcessAn application for a concealed carry permit shall be made to the sheriff of the county or any city not within a county in which the applicant resides. An application shall be filed in writing, signed under oath and under the penalties of perjury, and shall state whether the applicant complies with each of the requirements specified in subsection 2 of this section. In addition to the completed application, the applicant for a concealed carry permit must also submit the following:

1. A photocopy of a firearms safety training certificate of completion or other evidence of completion of a firearms safety training course that meets the standards established in subsection 1 or 2 of section 571.111; and
2. A nonrefundable permit fee:
   1. New application: $100
   2. Renewal application: $50

Mo. Rev. Stat. § 571.101 (4), (11), & (12)

Missouri law:

Any person issued a concealed carry permit pursuant to sections 571.101 to 571.121, or a concealed carry endorsement issued prior to August 28, 2013, shall carry the concealed carry permit or endorsement at all times the person is carrying a concealed firearm and shall display the concealed carry permit and a state or federal government-issued photo identification or the endorsement or permit upon the request of any peace officer. Failure to comply with this subsection shall not be a criminal offense but the concealed carry permit or endorsement holder may be issued a citation for an amount not to exceed thirty-five dollars.

Mo. Rev. Stat. § 571.121 (1)

Missouri law:

1. The general assembly hereby occupies and preempts the entire field of legislation touching in any way firearms, components, ammunition and supplies to the complete exclusion of any order, ordinance or regulation by any political subdivision of this state. Any existing or future orders, ordinances or regulations in this field are hereby and shall be null and void except as provided in subsection 3 of this section.
2. No county, city, town, village, municipality, or other political subdivision of this state shall adopt any order, ordinance or regulation concerning in any way the sale, purchase, purchase delay, transfer, ownership, use, keeping, possession, bearing, transportation, licensing, permit, registration, taxation other than sales and compensating use taxes or other controls on firearms, components, ammunition, and supplies except as provided in subsection 3 of this section.

Mo. Rev. Stat. § 21.750

Missouri law:

Missouri has no law requiring a background check on the purchaser of a firearm when the seller is not a licensed dealer. Missouri does, however, prohibit the following:

1. Knowingly selling, leasing, loaning, giving away or delivering a firearm to a person who is not entitled to possess the firearm under Missouri law;
2. Recklessly selling, leasing, loaning, giving away or delivering any firearm to a person under age 18 without the consent of the child’s custodial parent or guardian; or
3. Recklessly selling, leasing, loaning, giving away or delivering a firearm or ammunition to a person who is intoxicated.

Mo. Rev. Stat. § 571.070

Missouri has no laws restricting the ammunition capacity of magazines.

Missouri law:No permit will authorize a person to possess a firearm in the following locations:

1. Any police, sheriff, or highway patrol office or station without the consent of the chief law enforcement officer in charge of that office or station. Possession of a firearm in a vehicle on the premises of the office or station shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
2. Within twenty-five feet of any polling place on any election day. Possession of a firearm in a vehicle on the premises of the polling place shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
3. The facility of any adult or juvenile detention or correctional institution, prison or jail. Possession of a firearm in a vehicle on the premises of any adult, juvenile detention, or correctional institution, prison or jail shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
4. Any courthouse solely occupied by the circuit, appellate or supreme court, or any courtrooms, administrative offices, libraries or other rooms of any such court whether or not such court solely occupies the building in question. This subdivision shall also include, but not be limited to, any juvenile, family, drug, or other court offices, any room or office wherein any of the courts or offices listed in this subdivision are temporarily conducting any business within the jurisdiction of such courts or offices, and such other locations in such manner as may be specified by supreme court rule pursuant to subdivision (6) of this subsection. Nothing in this subdivision shall preclude those persons listed in subdivision (1) of subsection 2 of section 571.030 while within their jurisdiction and on duty, those persons listed in subdivisions (2), (4), and (10) of subsection 2 of section 571.030, or such other persons who serve in a law enforcement capacity for a court as may be specified by supreme court rule pursuant to subdivision (6) of this subsection from carrying a concealed firearm within any of the areas described in this subdivision. Possession of a firearm in a vehicle on the premises of any of the areas listed in this subdivision shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
5. Any meeting of the governing body of a unit of local government; or any meeting of the general assembly or a committee of the general assembly, except that nothing in this subdivision shall preclude a member of the body holding a valid concealed carry permit or endorsement from carrying a concealed firearm at a meeting of the body which he or she is a member. Possession of a firearm in a vehicle on the premises shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises. Nothing in this subdivision shall preclude a member of the general assembly, a full-time employee of the general assembly employed under Section 17, Article III, Constitution of Missouri, legislative employees of the general assembly as determined under section 21.155, or statewide elected officials and their employees, holding a valid concealed carry permit or endorsement, from carrying a concealed firearm in the state capitol building or at a meeting whether of the full body of a house of the general assembly or a committee thereof, that is held in the state capitol building;
6. The general assembly, supreme court, county or municipality may by rule, administrative regulation, or ordinance prohibit or limit the carrying of concealed firearms by permit or endorsement holders in that portion of a building owned, leased or controlled by that unit of government. Any portion of a building in which the carrying of concealed firearms is prohibited or limited shall be clearly identified by signs posted at the entrance to the restricted area. The statute, rule or ordinance shall exempt any building used for public housing by private persons, highways or rest areas, firing ranges, and private dwellings owned, leased, or controlled by that unit of government from any restriction on the carrying or possession of a firearm. The statute, rule or ordinance shall not specify any criminal penalty for its violation but may specify that persons violating the statute, rule or ordinance may be denied entrance to the building, ordered to leave the building and if employees of the unit of government, be subjected to disciplinary measures for violation of the provisions of the statute, rule or ordinance. The provisions of this subdivision shall not apply to any other unit of government;
7. Any establishment licensed to dispense intoxicating liquor for consumption on the premises, which portion is primarily devoted to that purpose, without the consent of the owner or manager. The provisions of this subdivision shall not apply to the licensee of said establishment. The provisions of this subdivision shall not apply to any bona fide restaurant open to the general public having dining facilities for not less than fifty persons and that receives at least fifty-one percent of its gross annual income from the dining facilities by the sale of food. This subdivision does not prohibit the possession of a firearm in a vehicle on the premises of the establishment and shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises. Nothing in this subdivision authorizes any individual who has been issued a concealed carry permit or endorsement to possess any firearm while intoxicated;
8. Any area of an airport to which access is controlled by the inspection of persons and property. Possession of a firearm in a vehicle on the premises of the airport shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
9. Any place where the carrying of a firearm is prohibited by federal law;
10. Any higher education institution or elementary or secondary school facility without the consent of the governing body of the higher education institution or a school official or the district school board, unless the person with the concealed carry endorsement or permit is a teacher or administrator of an elementary or secondary school who has been designated by his or her school district as a school protection officer and is carrying a firearm in a school within that district, in which case no consent is required. Possession of a firearm in a vehicle on the premises of any higher education institution or elementary or secondary school facility shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
11. Any portion of a building used as a child care facility without the consent of the manager. Nothing in this subdivision shall prevent the operator of a child care facility in a family home from owning or possessing a firearm or a concealed carry permit or endorsement;
12. Any riverboat gambling operation accessible by the public without the consent of the owner or manager pursuant to rules promulgated by the gaming commission. Possession of a firearm in a vehicle on the premises of a riverboat gambling operation shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
13. Any gated area of an amusement park. Possession of a firearm in a vehicle on the premises of the amusement park shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
14. Any church or other place of religious worship without the consent of the minister or person or persons representing the religious organization that exercises control over the place of religious worship. Possession of a firearm in a vehicle on the premises shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
15. Any private property whose owner has posted the premises as being off-limits to concealed firearms by means of one or more signs displayed in a conspicuous place of a minimum size of eleven inches by fourteen inches with the writing thereon in letters of not less than one inch. The owner, business or commercial lessee, manager of a private business enterprise, or any other organization, entity, or person may prohibit persons holding a concealed carry permit or endorsement from carrying concealed firearms on the premises and may prohibit employees, not authorized by the employer, holding a concealed carry permit or endorsement from carrying concealed firearms on the property of the employer. If the building or the premises are open to the public, the employer of the business enterprise shall post signs on or about the premises if carrying a concealed firearm is prohibited. Possession of a firearm in a vehicle on the premises shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises. An employer may prohibit employees or other persons holding a concealed carry permit or endorsement from carrying a concealed firearm in vehicles owned by the employer;
16. Any sports arena or stadium with a seating capacity of five thousand or more. Possession of a firearm in a vehicle on the premises shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises;
17. Any hospital accessible by the public. Possession of a firearm in a vehicle on the premises of a hospital shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises.

Mo. Rev. Stat. § 571.107 (1)

PenaltiesCarrying of a concealed firearm in a location specified in subdivisions (1) to (17) of subsection 1 of this section by any individual who holds a concealed carry permit issued pursuant to sections 571.101 to 571.121, or a concealed carry endorsement issued prior to August 28, 2013, shall not be a criminal act but may subject the person to denial to the premises or removal from the premises. If such person refuses to leave the premises and a peace officer is summoned, such person may be issued a citation for an amount not to exceed one hundred dollars for the first offense. If a second citation for a similar violation occurs within a six-month period, such person shall be fined an amount not to exceed two hundred dollars and his or her permit, and, if applicable, endorsement to carry concealed firearms shall be suspended for a period of one year. If a third citation for a similar violation is issued within one year of the first citation, such person shall be fined an amount not to exceed five hundred dollars and shall have his or her concealed carry permit, and, if applicable, endorsement revoked and such person shall not be eligible for a concealed carry permit for a period of three years. Upon conviction of charges arising from a citation issued pursuant to this subsection, the court shall notify the sheriff of the county which issued the concealed carry permit, or, if the person is a holder of a concealed carry endorsement issued prior to August 28, 2013, the court shall notify the sheriff of the county which issued the certificate of qualification for a concealed carry endorsement and the department of revenue. The sheriff shall suspend or revoke the concealed carry permit or, if applicable, the certificate of qualification for a concealed carry endorsement. If the person holds an endorsement, the department of revenue shall issue a notice of such suspension or revocation of the concealed carry endorsement and take action to remove the concealed carry endorsement from the individual's driving record. The director of revenue shall notify the licensee that he or she must apply for a new license pursuant to chapter 302 which does not contain such endorsement. The notice issued by the department of revenue shall be mailed to the last known address shown on the individual's driving record. The notice is deemed received three days after mailing.

Mo. Rev. Stat. § 571.107 (2)

Missouri law allows open carry without a permit. However, open carry is one area where the state does not have preemption, so cities may restrict open carry.

Missouri law:

The following is included among prohibited areas in Missouri:

Any private property whose owner has posted the premises as being off-limits to concealed firearms by means of one or more signs displayed in a conspicuous place of a minimum size of eleven inches by fourteen inches with the writing thereon in letters of not less than one inch. The owner, business or commercial lessee, manager of a private business enterprise, or any other organization, entity, or person may prohibit persons holding a concealed carry permit or endorsement from carrying concealed firearms on the premises and may prohibit employees, not authorized by the employer, holding a concealed carry permit or endorsement from carrying concealed firearms on the property of the employer. If the building or the premises are open to the public, the employer of the business enterprise shall post signs on or about the premises if carrying a concealed firearm is prohibited. Possession of a firearm in a vehicle on the premises shall not be a criminal offense so long as the firearm is not removed from the vehicle or brandished while the vehicle is on the premises. An employer may prohibit employees or other persons holding a concealed carry permit or endorsement from carrying a concealed firearm in vehicles owned by the employer;

Mo. Rev. Stat. § 571.107 (1) (15)

Missouri law:A person commits the offense of unlawful use of weapons, except as otherwise provided by sections 571.101 to 571.121, if he or she knowingly:

• Has a firearm or projectile weapon readily capable of lethal use on his or her person, while he or she is intoxicated, and handles or otherwise uses such firearm or projectile weapon in either a negligent or unlawful manner or discharges such firearm or projectile weapon unless acting in self-defense; or

Mo. Rev. Stat. § 571.030 (1) (5)

Missouri law:

Subdivisions (1), (5), (8), and (10) of subsection 1 of [the Unlawful-Use-of-Weapons law] do not apply when the actor is transporting such weapons in a nonfunctioning state or in an unloaded state when ammunition is not readily accessible or when such weapons are not readily accessible. Subdivision (1) of subsection 1 of this section does not apply to any person nineteen years of age or older or eighteen years of age or older and a member of the United States Armed Forces, or honorably discharged from the United States Armed Forces, transporting a concealable firearm in the passenger compartment of a motor vehicle, so long as such concealable firearm is otherwise lawfully possessed, nor when the actor is also in possession of an exposed firearm or projectile weapon for the lawful pursuit of game, or is in his or her dwelling unit or upon premises over which the actor has possession, authority or control, or is traveling in a continuous journey peaceably through this state.

Mo. Rev. Stat. § 571.030 (3)

Missouri does not have any laws specifically related to how firearms must be stored.

Missouri law:

Any person issued a concealed carry permit pursuant to sections 571.101 to 571.121, or a concealed carry endorsement issued prior to August 28, 2013, shall carry the concealed carry permit or endorsement at all times the person is carrying a concealed firearm and shall display the concealed carry permit and a state or federal government-issued photo identification or the endorsement or permit upon the request of any peace officer. Failure to comply with this subsection shall not be a criminal offense but the concealed carry permit or endorsement holder may be issued a citation for an amount not to exceed thirty-five dollars.

Mo. Rev. Stat. § 571.121 (1)

Missouri does not have Emergency Risk Orders ("Red Flag Laws).

Missouri law:

1. A person may, subject to the provisions of subsection 2 of this section, use physical force upon another person when and to the extent he or she reasonably believes such force to be necessary to defend himself or herself or a third person from what he or she reasonably believes to be the use or imminent use of unlawful force by such other person, unless:
   1. The actor was the initial aggressor; except that in such case his or her use of force is nevertheless justifiable provided:
      1. He or she has withdrawn from the encounter and effectively communicated such withdrawal to such other person but the latter persists in continuing the incident by the use or threatened use of unlawful force; or
      2. He or she is a law enforcement officer and as such is an aggressor pursuant to section 563.046; or
      3. The aggressor is justified under some other provision of this chapter or other provision of law;
   2. Under the circumstances as the actor reasonably believes them to be, the person whom he or she seeks to protect would not be justified in using such protective force;
   3. The actor was attempting to commit, committing, or escaping after the commission of a forcible felony.
2. A person shall not use deadly force upon another person under the circumstances specified in subsection 1 of this section unless:
   1. He or she reasonably believes that such deadly force is necessary to protect himself, or herself or her unborn child, or another against death, serious physical injury, or any forcible felony;
   2. Such force is used against a person who unlawfully enters, remains after unlawfully entering, or attempts to unlawfully enter a dwelling, residence, or vehicle lawfully occupied by such person; or
   3. Such force is used against a person who unlawfully enters, remains after unlawfully entering, or attempts to unlawfully enter private property that is owned or leased by an individual, or is occupied by an individual who has been given specific authority by the property owner to occupy the property, claiming a justification of using protective force under this section.

Mo. Rev. Stat. § 563.031 (1) & (2)

Missouri does not have a law specific to the defense of others, but does allow for the defense of a third person in its defense-of-person law.

Missouri law:

A person shall not use deadly force upon another person under the circumstances specified in subsection 1 of this section unless:

1. Such force is used against a person who unlawfully enters, remains after unlawfully entering, or attempts to unlawfully enter a dwelling, residence, or vehicle lawfully occupied by such person; or
2. Such force is used against a person who unlawfully enters, remains after unlawfully entering, or attempts to unlawfully enter private property that is owned or leased by an individual, or is occupied by an individual who has been given specific authority by the property owner to occupy the property, claiming a justification of using protective force under this section.

Mo. Rev. Stat. § 563.031 (2)

Missouri law:

1. A person may, subject to the limitations of subsection 2, use physical force upon another person when and to the extent that he or she reasonably believes it necessary to prevent what he or she reasonably believes to be the commission or attempted commission by such person of stealing, property damage or tampering in any degree.
2. A person may use deadly force under circumstances described in subsection 1 only when such use of deadly force is authorized under other sections of this chapter.
3. The justification afforded by this section extends to the use of physical restraint as protective force provided that the actor takes all reasonable measures to terminate the restraint as soon as it is reasonable to do so.

Mo. Rev. Stat. § 563.041

Missouri does not have any laws specifically related to self-defense immunity.

Missouri law:
A person does not have a duty to retreat:

1. From a dwelling, residence, or vehicle where the person is not unlawfully entering or unlawfully remaining;
2. From private property that is owned or leased by such individual; or
3. If the person is in any other location such person has the right to be.

Mo. Rev. Stat. § 563.031 (3)

Dogs may be killed, when

If any person shall discover any dog or dogs in the act of killing, wounding or chasing sheep in any portion of this state, or shall discover any dog or dogs under such circumstances as to satisfactorily show that such dog or dogs has or have been recently engaged in killing or chasing sheep or other domestic animal or animals, such person is authorized to immediately pursue and kill such dog or dogs; provided, however, that such dog or dogs shall not be killed in any enclosure belonging to or being in lawful possession of the owner of such dog or dogs.

Mo. Rev. Stat. § 273.030

Killing or injuring a dog, reasonable apprehension of imminent harm is an absolute defense

1. In any action for damages or a criminal prosecution against any person for killing or injuring a dog, a showing by a preponderance of the evidence that such person was in reasonable apprehension of imminent harmful contact by the dog or was acting to prevent such imminent harmful contact against another person by the dog shall constitute an absolute defense to criminal prosecution or civil liability for the killing or injuring of such animal.
2. If a person has, on at least two occasions, complained to the county sheriff or to the appropriate animal control authority in his or her jurisdiction that a dog, not on a leash, has trespassed on property that such person owns, rents, or leases or on any property that constitutes such person's residence, and when at least one of the prior two complaints was motivated by reasonable apprehension for such person's safety or the safety of another person or apprehension of substantial damage to livestock or property, then any subsequent trespass by such dog shall constitute prima facie evidence that such person was in reasonable apprehension of imminent harmful contact. The county sheriff or animal control authority to which any complaint under this section is made shall notify the owner of the alleged trespassing dog of such complaint. Failure by a county sheriff or animal control authority to notify a dog owner under this subsection shall not invalidate or be construed in any way to limit any other provision of this subsection.

Mo. Rev. Stat. § 273.033

563.074. Justification as an absolute defense, when. —

1. Notwithstanding the provisions of section 563.016, a person who uses force as described in sections 563.031, 563.041, 563.046, 563.051, 563.056, and 563.061 is justified in using such force and such fact shall be an absolute defense to criminal prosecution or civil liability.

2. The court shall award attorney's fees, court costs, and all reasonable expenses incurred by the defendant in defense of any civil action brought by a plaintiff if the court finds that the defendant has an absolute defense as provided in subsection 1 of this section.