Zed of course I read your comments. It seems to me the sabs have the evidence, why can't the police use that?
Milvus I agree. My two cats both wore a collar with a bell to at least give the wildlife a chance, plus I kept them in (with difficulty) at dawn and dusk during the spring and early summer while the juvenile, fledgeling and baby birds were about. But while my cats were indoors, the neighbours cats were doing the damage.
No matter how much I have tried I have never managed to persuade a friend or a neighbour to take seriously the fact that their cats kill our wildlife. It's usually talk to the hand the face ain't listening. Only one person ever agreed to put a collar on her cat, a small miracle. I only have the one cat now and she is in her 20th year and goes outside for about 5 seconds a week and it is such a relief to know she's indoors where she can't harm any living thing except me. It's heart breaking when you've put up next boxes and feeders plus live mealworms to support the birds only to find the whole lot have been killed, one by one, by a bl00dy cat.