Ok I'm going chime in on the cam thing. I had a neighbor that was dumping garbage behind my garage. It was the same spot for the weekly pick up but the law which no one follows says only after 6:00pm the day before. Well this prick was doing whenever he felt like it. He was putting boxes of old telephones to rotted fruit back there. I posted signs warning I would call the police and he would just rip the sign off. Well he really pissed me off when he started to throw crap on the roof of my garage.
I started looking into getting a camera system and the research I found was that you are going to need get a high end system that will produce a quality picture. Also you say this is happening at night which means you will need an infrared camera which will run the cost up ever more. Also anyone suggesting a 39.99 cam has no experience in this. Believe me I research this pretty hard.
To get someone on cam and use it in court you are going need video that is not blurred to hold up in court. If your video shows some black blob in the video it will do you no good. The second thing I suggest is to get a cam that will show the time and date on the video. This will help your case. Also do not point the cam directly at your neighbors house because that will get you in trouble. Coworker had a problem with his neighbors and pointed it at their neighbors house and he had to pay a fine for it when he took them to court. So point the cam only at your side of the house. Also since you have no damage the cop will tell you this is a civil matter and you will have to file with the local magistrate.
http://www.logitech.com/en-us/webcam-communications/video-security-systems/master-systems/7252 Logitech Alert 750e Outdoor Master System is what I bought. Am I totally happy with it? Nope I have the cam set up about 25 yards a way where I needed it and the video is iffy from that distant. Also this cam is not wireless so double whammy. I did get enough on the cam to recognize who it was because his little back dog that he walks 3 times day was in the video. I paid that asshole a visit and he about shit his pants. I flipped the fuck out on him. The very next day I have him on cam cleaning my roof off and he never dump his trash there again.