Reviewing the Missouri state code, the dog NOT in the trap is subject to his word. With no witnesses, his assertion that the dog became aggressive will be irrefutable beyond a reasonable doubt in court; however, the dog trapped in the leg hold trap is another story. It was captured and unable to escape. There is probably some civil action (sue him into the ground) that can be taken there. Dogs commonly find themselves trapped in leg hold traps and survive. This should eliminate any "mercy killing" that this person claimed. The code says the animals have to be OFF their property AND attacking to give the shooter grounds to shoot.
Report him to the game department. Is he hunting or trapping out of season? This angle may be one to hit him with. You could always place an add in the local paper warning people that this "gun toting animal killer" is loose and they should protect their pets. His picture and the two dogs shown with the family may raise some public sentiment against him. Run him out of town instead...
CODE attached - section in BOLD
Missouri Cruelty to Animals Statutes
TITLE XXXVIII. CRIMES AND PUNISHMENT;
PEACE OFFICERS AND PUBLIC DEFENDERS
CHAPTER 578. MISCELLANEOUS OFFENSES
As used in sections 578.005 to 578.023, the following terms shall mean:
(1) "Adequate care", normal and prudent attention to the needs of an animal, including wholesome food, clean water, shelter and health care as necessary to maintain good health in a specific species of animal;
(2) "Adequate control", to reasonably restrain or govern an animal so that the animal does not injure itself, any person, any other animal, or property;
(3) "Animal", every living vertebrate except a human being;
(4) "Animal shelter", a facility which is used to house or contain animals and which is owned, operated, or maintained by a duly incorporated humane society, animal welfare society, society for the prevention of cruelty to animals, or other not for profit organization devoted to the welfare, protection, and humane treatment of animals;
(5) "Farm animal", an animal raised on a farm or ranch and used or intended for use in farm or ranch production, or as food or fiber;
(6) "Harbor", to feed or shelter an animal at the same location for three or more consecutive days;
(7) "Humane killing", the destruction of an animal accomplished by a method approved by the American Veterinary Medical Association's Panel on Euthanasia (JAVMA 173: 59-72, 1978); or more recent editions, but animals killed during the feeding of pet carnivores shall be considered humanely killed;
(8) "Owner", in addition to its ordinary meaning, any person who keeps or harbors an animal or professes to be owning, keeping, or harboring an animal;
(9) "Person", any individual, partnership, firm, joint stock company, corporation, association, trust, estate, or other legal entity;
(10) "Pests", birds, rabbits, or rodents which damage property or have an adverse effect on the public health, but shall not include any endangered species listed by the United States Department of the Interior nor any endangered species listed in the Wildlife Code of Missouri.
578.007. Acts and facilities to which sections 578.005 to 578.023 do not apply
The provisions of sections 578.005 to 578.023 shall not apply to:
(1) Care or treatment performed by a licensed veterinarian within the provisions of chapter 340, RSMo;
(2) Bona fide scientific experiments;
(3) Hunting, fishing, or trapping as allowed by chapter 252, RSMo, including all practices and privileges as allowed under the Missouri Wildlife Code;
(4) Facilities and publicly funded zoological parks currently in compliance with the federal "Animal Welfare Act" as amended;
(5) Rodeo practices currently accepted by the Professional Rodeo Cowboy's Association;
(6) The killing of an animal by the owner thereof, the agent of such owner, or by a veterinarian at the request of the owner thereof;
(7) The lawful, humane killing of an animal by an animal control officer, the operator of an animal shelter, a veterinarian, or law enforcement or health official;
(8) With respect to farm animals, normal or accepted practices of animal husbandry;
(9) The killing of an animal by any person at any time if such animal is outside of the owned or rented property of the owner or custodian of such animal and the animal is injuring any person or farm animal but shall not include police or guard dogs while working;
(10) The killing of house or garden pests; or
(11) Field trials, training and hunting practices as accepted by the Professional Houndsmen of Missouri.
578.009. Animal neglect--penalties--costs and expenses
1. A person is guilty of animal neglect when he has custody or ownership or both of an animal and fails to provide adequate care or adequate control, which results in substantial harm to the animal.
2. A person is guilty of abandonment when he has knowingly abandoned an animal in any place without making provisions for its adequate care.
3. Animal neglect and abandonment is a class C misdemeanor upon first conviction and for each offense, punishable by imprisonment or a fine not to exceed five hundred dollars, or both, and a class B misdemeanor punishable by imprisonment or a fine not to exceed one thousand dollars, or both upon the second and all subsequent convictions. All fines and penalties for a first conviction of animal neglect or abandonment may be waived by the court provided that the person found guilty of animal neglect or abandonment shows that adequate, permanent remedies for the neglect or abandonment have been made. Reasonable costs incurred for the care and maintenance of neglected or abandoned animals may not be waived. This section shall not apply to the provisions of section 578.007.
4. In addition to any other penalty imposed by this section, the court may order a person found guilty of animal neglect or abandonment to pay all reasonable costs and expenses necessary for:
(1) The care and maintenance of neglected or abandoned animals within the person's custody or ownership;
(2) The disposal of any dead or diseased animals within the person's custody or ownership;
(3) The reduction of resulting organic debris affecting the immediate area of the neglect or abandonment; and
(4) The avoidance or minimization of any public health risks created by the neglect or abandonment of the animals.
578.012. Animal abuse--penalties
1. A person is guilty of animal abuse when a person:
(1) Intentionally or purposely kills an animal in any manner not allowed by or expressly exempted from the provisions of sections 578.005 to 578.023 and 273.030, RSMo;
(2) Purposely or intentionally causes injury or suffering to an animal; or
(3) Having ownership or custody of an animal knowingly fails to provide adequate care or adequate control.
2. Animal abuse is a class A misdemeanor, unless the defendant has previously plead guilty to or has been found guilty of animal abuse or the suffering involved in subdivision (2) of subsection 1 of this section is the result of torture or mutilation, or both, consciously inflicted while the animal was alive, in which case it is a class D felony.
578.014. Responsibility of parent or guardian of minor owning
The parent or guardian of a minor child is responsible for the adequate care of any animal owned by, in the control of, or harbored by that minor child.
578.016. Impoundment of animal found off property of owner or custodian, disposition, procedure--liability of owner or custodian for costs--lien-- rights of owner or custodian
1. Any duly authorized public health official, law enforcement official, or animal control officer may impound any animal found outside of the owned or rented property of the owner or custodian of such animal when such animal shows evidence of neglect or abuse. Any animal impounded pursuant to this section shall be:
(1) If the owner can be ascertained and the animal is not diseased or disabled beyond recovery for any useful purpose, held for recovery by the owner. The owner shall be notified within five business days of impoundment by phone or by mail of the animal's location and recovery procedures. The animal shall be held for ten business days. An animal unclaimed after ten business days may be put up for adoption or humanely killed;
(2) Placed in the care or custody of a veterinarian, the appropriate animal control authority or animal shelter. The animal shall not be disposed of, unless diseased or disabled beyond recovery for any useful purpose, until after expiration of a minimum of five business days, during which time the public shall have clear access to inspect or recover the animal through time periods ordinarily accepted as usual business hours. After five business days, the animal may be put up for adoption or humanely killed; or
(3) If diseased or disabled beyond recovery for any useful purpose as determined by a public health official, law enforcement official, veterinarian or animal control officer, humanely killed.
2. The owner or custodian of an animal impounded pursuant to this section shall be liable for reasonable costs for the care and maintenance of the animal. Any person incurring reasonable costs for the care and maintenance of such animal shall have a lien against such animal until the reasonable costs have been paid and may put up for adoption or humanely kill any animal if such costs are not paid within ten days after demand. Any moneys received for an animal adopted pursuant to this subsection in excess of costs shall be paid to the owner of such animal.
3. The owner or custodian of any animal killed pursuant to this section shall be entitled to recover the actual value of the animal up to but not to exceed six hundred dollars if the owner or custodian shows that such killing was unwarranted.
578.018. Warrant for entry on private property to inspect--impounded animals--compensation
1. Any duly authorized public health official or law enforcement official may seek a warrant from the appropriate court to enable him to enter private property in order to inspect, care for, or impound neglected or abused animals. All requests for such warrants shall be accompanied by an affidavit stating the probable cause to believe a violation of sections 578.005 to 578.023 has occurred. A person acting under the authority of a warrant shall:
(1) Be given a disposition hearing before the court through which the warrant was issued, within thirty days of the filing of the request for the purpose of granting immediate disposition of the animals impounded;
(2) Place impounded animals in the care or custody of a veterinarian, the appropriate animal control authority, or an animal shelter. If no appropriate veterinarian, animal control authority, or animal shelter is available, the animal shall not be impounded unless it is diseased or disabled beyond recovery for any useful purpose;
(3) Humanely kill any animal impounded if it is determined by a licensed veterinarian that the animal is diseased or disabled beyond recovery for any useful purpose;
(4) Not be liable for any necessary damage to property while acting under such warrant.
2. The owner or custodian or any person claiming an interest in any animal that has been impounded because of neglect or abuse may prevent disposition of the animal by posting bond or security in an amount sufficient to provide for the animal's care and keeping for at least thirty days, inclusive of the date on which the animal was taken into custody. Notwithstanding the fact that bond may be posted pursuant to this subsection, the authority having custody of the animal may humanely dispose of the animal at the end of the time for which expenses are covered by the bond or security, unless there is a court order prohibiting such disposition. Such order shall provide for a bond or other security in the amount necessary to protect the authority having custody of the animal from any cost of the care, keeping or disposal of the animal. The authority taking custody of an animal shall give notice of the provisions of this section by posting a copy of this section at the place where the animal was taken into custody or by delivering it to a person residing on the property.
3. The owner or custodian of any animal humanely killed pursuant to this section shall not be entitled to recover any damages related to nor the actual value of the animal if the animal was found by a licensed veterinarian to be diseased or disabled, or if the owner or custodian failed to post bond or security for the care, keeping and disposition of the animal after being notified of impoundment.
578.021. Neglected or abused animal not to be returned to owner or custodian, when
If a person is adjudicated guilty of the crime of animal neglect or animal abuse and the court having jurisdiction is satisfied that an animal owned or controlled by such person would in the future be subject to such neglect or abuse, such animal shall not be returned to or allowed to remain with such person, but its disposition shall be determined by the court.