I have never known of a stalking case where the police were of any use at all. In my family tree I have known quite a few truly dangerous stalkers (my father, my mother, 2 uncles on my mothers side, an uncle on my fathers side, and 3 brothers... one generation taught the next...) - and I have been married/separated from one for many, many years now. The police do nothing.
My father, 1 of the uncles, and 1 brother did truly horrific crimes to their victims, and never ever spent even one day in jail. Another brother got 'slapped on the wrist' many times with probation before he finally spent a year. He continued his crimes once released. For the saving grace of his victims he finally took his own life when he was heading back to prison the second time. But, by then he had a really long list of victims. My father had a longer list of victims, and never spent a day. My uncle slit his wife's throat 'ear to ear' twice for leaving him - the second time right in front of the police station. She survived, but decided she likely wouldn't survive a 3rd time, so she never left him again; just lived with the horrific life he put her through. He never spent a day in prison for either attempted murder. I was a teenager at the time, and still do not understand how he could get away with that.