Im sorry for the long post but this is freaking out. please help me do something to stop this

As I was driving home from the ACE hardware on 29th and I made a left turn down to 26th. I was abruptly greeted with his middle finger as he got into his car to show me his threat still stands? or simply because I was driving home Children live in this neighborhood. I don't know how to make this stop. but it is freaking me out to say the least.

He does not come out of his fenced off yard or even his house when I am walking my dog since the first incident (thank god) but the second he saw me driving home 5/1/14 he flipped me off just to "show me" he is still angry and hasn't forgotten his threat?. I am a caretaker for my mother with M.S. and am worried he will come by my house and threaten my mother and or me based on what he has said. I will of course call the police if this happens but it will take a bit for them to get here, so I must deal with him till police do arive thats a problem too. do but should this really be necessary. I haven't seen him since my last post, or done anything, seenor offended him in any way.. All I have done is have the nerve to walk my dog every morning around the block. at 730 8 am    This is the same man who threatened to "bring all kinds of hell down on to me about one month ago.  over dog poop (that I do pick up) How far will this go? 

Please someone at least acknowledge this has been read/ noticed. Again, I don't know what to do. I hear the neighborhood watch leader is married to a police officer. Please help me/ my mom this is getting VERY out of hand This is a grown man for gods sake!

Should I need to avoid his home at all costs?? Really?!