This has been happening for years and is getting much worse. JPD seems helpless to do anything definitive about the problem. There's no question about it's being illegal stalking and threatening had harassment but no one seems willing to help, not the city attorney's office, no one.
Unless you have concrete proof and it is more than just a nuisance -- doubt they'll take up the cause. If you fear for your safety or the safety of your premises, then they may act.
Can you ask for a patrol car to drive by while you are on the street? Can you go out in gangs of seniors for self-defense?
Is there anyone in the community who could help you? Is there a church or a VFW or a senior center? Is everyone in the neighborhood in on this? Can you get in touch with the local newspaper, TV or radio station?
Are there other elders in your neighborhood?
Do they have the same problems?
Is there something different about you that attracted these hooligans such as a different ethnic background?
Do you own or rent your home?
If it is rented look to move somewhere safer in the area till your husband retires or sell and rent if that works too.
Just get out ASAP