There are supposed to be, but I don't think they are anonymous. I have wanted to report crimes but most of the time I don't get involved because it is time consuming and they can easily find out who reported the crime.
There was a man and woman shooting a high powered rifle in my homes direction. I went out and told the people that the gun was scaring my animals and not to be shooting from the roadway. I had to go to turn around and the man started reloading his rifle like there was going to be a shootout. I called the police with the car license plate number and they gave me his home address. I went to see where he lived and it was a cheap looking trailer park. The police are very open with information where I live. If you know one of them you can get your tickets fixed or whatever you want. If you get a persons license number and call the sheriffs department, they give the persons home address without question.