George, call some of the city council members there local. Ask them why NOTHING is being done, and show them your file. Tell them you've done all the police work, and that their detective staff needs to get more aggressive. YOUR home and you were violated when these thugs came in your house, while your fiancé was asleep inside! Go to the city council meeting and say it at the podium, with the mic on and the TV cameras running (most local council meetings are televised). Believe me, what you need is a couple city council members asking your city manager and police chief why NOTHING is being done more aggressive before someone elses home is intruded upon.
Trust me being in local government, I see it all the time. Sometimes it takes a little voicing your opinion to the public, and a couple council members putting pressure on the police chief and city manager to move on some thing, and get to the bottom of it.
If you live in the township, then your dealing with the sheriff and township trustees. You will have much more luck with this method if your in the city, and dealing with a local PD that answer to a city manager and city council members.