Is the fence yours or his or shared? If it's not his then get some clear silicone sealant along the bottom edge where it meets the wall.
If he starts throwing it over the fence then the gloves come off and I would pay him a visit and shove it down his throat.
I'd write to your Police Chief Constable or whoever is top of the tree stating that you reported a neighbour leaving poisons unprotected near children to the Police who did nothing and ask him if he thinks this is acceptable, or do you have to wait till a child dies before they will consider it a serious matter.
If you still aren't satisfied with the response, get the names and serial/shoulder numbers of the officers involved and contact the chief constable for your area.
do people really believe when the write to the Big Boss of anything it has any effect other than to get slowly passed down the chain of command until it lands with somebody who's job it is to actually deal with it? If you are unhappy with police inaction, complain to the local inspector; they'll be the person who would ultimately deal with any complaint resolution after its spent 2 weeks cascading down through peoples in-trays.
As for being reported for trespass, that's bollocks. Trespass is a civil offence, not criminal. The police won't be interested unless they can show that criminal damage has been caused. Tripping over an aerial cable is an accident, not deliberate...
....and criminal damage can be (subjectively) reckless, not merely intentional....
If anything, you could claim damages of your neighbour for causing an accident
your'e just making this up as you go along now, aren't you?
