It's a common misunderstanding of feline behaviour - equally true of big cat species as in the small cats.
Cats will only bury their waste in what they see as their core territory. They will leave unburied waste on the edges of their territory to emphasise their claims to said territory or where there is a dispute between different cats over what "belongs" to whom.
So throwing cat poo over the fence into a neighbour's garden isn't a solution. The cat may not even be their cat. Cats' territories can be quite large, so please do not assume and pass the buck to someone who may well be totally blameless. The cat in question could live up to half a mile away. More if it's an entire as opposed to a neuter. Cats will always return to use a latrine or to mark their territory - the best solution is to use a doggy poop scoop, bag it up and bin it. Cats have very sensitive feet, so put down things like sharp gravel or slate chippings that make the area less desirable to use. And don't use bleach to clean up as the scent of ammonia will only encourage them to return to the spot.
A note to also bear in mind - some people will lock their cats outside when they are out or asleep, which means that they do not have access to a litter tray during that time. The issue of cat soiling is as much a problem caused by Humans as it is caused by cats, who sometimes may not have a choice over where they toilet. Imagine if all the public loos were suddenly closed and you were bursting. What would you do?
Incidentally, my two refuse to poop outside - they will come in to do that. I am treated to the comedy act of Lexi pooping in the downstairs tray and Poppy waiting next to the tray to cover Lexi's deposits as Lexi apparently never does it to her satisfaction.
Edited to add a point: Are you sure it's cat poo? It could equally be fox poo.
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