Of course I don't mean to get you guys all started again with retaliation ideas (other thread got closed because of that), but because some of you really wanted to help, I thought I would update you on what happened thus far. When the sign was up for the first day (it reads "Please pick up your dog's waste. It's the law and we know who you are"), the suspect walked by with his dog and read the sign. It was around 9pm and I was monitoring the activity that night. After that I was about to talk to him, but he purposely walked away fast and when he noticed that I was looking at the direction he was walking, he walked slowly so I wouldn't know where he lives. He disappeared somewhere between two house but I know now that he lives 4 houses away from me. New in the neighborhood and the problem started when he moved in. So anyway, now that he is aware that I know, I don't think he'll let his dog do it freeing at my lawn anymore. Also, I found at a hardware store a spray that you spray on soil and plants to deter animals. It's made of spicey herds. It's harmless to animals but it's not very pleasant for them to sniff it. So anyway, I hope the problem is solved. Thanks for everyone who tried to help.