I come from one of the wildest remaining areas in the lower 48, with a correspondingly high density of charismatic megafauna and apex predators.
On exactly zero occasions have I ever witnessed the police or sheriff's deputies interacting with wildlife. There are specialized (and very heavily armed) government divisions for that sort of thing, and the vanilla police would spark a turf conflict by stepping in.
For example, it is common to see Fish and Wildlife department employees tranquilize and cage a grizzly bear in someone's yard, or to find the Animal Control division running a family of moose out of town, or to see NPS Rangers on horseback herd wild bison. I have even seen crews of municipal snipers deployed to reduce mule deer populations in town.
No sane person would deny very heavy weapons to the men who come face to face with grizzly bears in their daily life. Similarly, the deer sharpshooters should undoubtedly have long and powerful rifles with fancy optics.
But that is certainly not an argument for supporting the militarization and firepower expansion of the ordinary police.
This is only true for a very small handful of remote areas where few of the US Population live.
[1] http://www.sfgate.com/outdoors/article/Coyotes-seemingly-thr...
[2] http://www.sfgate.com/bayarea/article/Palo-Alto-visit-fatal-...
[3] http://www.nbcbayarea.com/news/local/Report-of-Mountain-Lion...
I'm not sure I buy wild animals as a reason for cops to carry guns, but there's a lot more of wild animals in a lot more places than you seem to think.
And avoidance is generally the best policy, but it's not an option for the police. So it's better than nothing, and there have been successful stops of bear attacks with these sorts of handguns.
Hmmm, a downside of replacing the police shotgun with "patrol carbines" (AR-15 variants, generally), you could always use slugs in the former, which are effective against bears.
That said, the idea that someone would need to carry a gun in that area to protect them from coyotes is laughable.
Secondly, in the US, we have the right to keep and bear arms, which means every one the routine patrol officer encounters should be assumed to be legally armed as well. It would put officers at a severe disadvantage to be unarmed when regularly dealing with armed suspects. In many states 5-10% of the population has a concealed carry permit, and in the majority (40+) of states open carry of a rifle is legal without any permit. Whether you agree with this or not, it's a fact of life in most of the US that a large percent of the population is legally armed, so there seems no reason to arbitrarily limit police from also being armed as any individual citizen could be.