After I posted the previous item on the gorilla said to be rampaging through Kansas City, the original article was updated (same link) and the ape in question is now reported to be a "large chimpanzee" (pan troglodytes) rather than a gorilla (gorilla gorilla).
The pictures in the original article were pretty blurry, but based on this video, apparently taken from a cellphone and which I dearly wish I could embed, it should have been obvious to anyone who has ever watched TV that this was not a gorilla. It is hard to tell how "large" this chimp is compared to other chimps, although given that chimps can rip your face off, you might as well consider any chimp large, armed and dangerous.
Certainly, the officers were wise to stay in their car when the chimp, identified as "Sueko," climbed onto it (after dragging a trash can over to use as a step!) and smashed the windshield. It is also clear that this is the most exciting thing that has ever happened to the people taking the video, who apparently (from experience or observation) know Sueko can open car doors. They convey this to the police by shrieking, "HE OPENS CAR DOORS!" so you might want to turn down the volume. Sueko's owner arrives right about then, which seems like especially bad timing.
I also have an answer to my question whether it is legal to own or harbor gorillas (or other primates) in Missouri. The answer seems to be yes, under state law, but maybe not under your local city ordinance. (This might be a good place to reiterate my usual disclaimer that you should not rely on anything I say here as accurate or binding legal advice. When you start paying me to research gorilla law, then you can hold me responsible.)
A Missouri statute provides that no person may keep any nonhuman primate (or lion, tiger, leopard, ocelot, jaguar, cheetah, margay, mountain lion, Canada lynx, bobcat, jaguarundi, hyena, wolf, bear, coyote, any "deadly, dangerous, or poisonous reptile," or any "deadly or dangerous reptile over eight feet long," so seven-foot poisonous reptiles are okay?) in any place other than a zoo, lab, etc., unless the animal has been registered. Mo. Rev. Stat. § 578.023. That implies, at least, that registered nonhuman primates (and so forth) could legally be kept at home. (See disclaimer above.)
But a Kansas City ordinance prohibits keeping certain exotic animals, including nonhuman primates. Code of Ordinances § 14-9. One could argue that the local rule is preempted by the state law, but just because that law doesn't expressly preclude keeping chimps (or hyenas or jaguarundis) doesn't mean it is expressly permitted, so the city can probably do this. Even if this were legal, that wouldn't mean it would be a good idea to keep these animals around, and it isn't. (Obviously Sueko was not happy with the situation.) The report now is that Sueko has been moved to a wildlife preserve, so that at least is an improvement.
I also want to again praise the officers, who -- contrary to the predictions of the video people ("I think they're gonna shoot him!") -- didn't shoot him.