they can get called to someones house a million times but until the person commits an offence there isnt anything they can do.
A nurse in the UK got stabbed to death outside the hospital she worked by her ex boyfriend, she had multiple death threats from him and her parent told police he was going to kill her, they just said, until he does something we cant act.
In the U.S. and specifically in Texas as I know Texas laws better than I know every other state but they are likely similar, calls to a location is one part of the pie in determining what steps can be taken. If they are common disturbances calls, i.e. neighbor calls in they hear loud yelling next door and the police arrive, they will check the occupants and try and determine the extent of the conflict. If it was verbal only, or if the occupants are untruthful regarding any force which is not uncommon and there are no complaints of pain or visible physical injury then the police attempt to calm the situation and offer suggestions like "Why don't you think about spending the night elsewhere until everyone calms down. They leave and write an offense report on what they found. There is that balance between policing and intruding that is always present. Often times we KNOW it's likely he or she is probably going to end up getting beaten but without probable cause to believe an offense has been committed our hands are tied.
There were a number of addresses officers in any given sector knew by heart due to the number of times they have had to respond. Any number of resources were offered from Crisis Intervention to Mental Health evaluations. Sometimes things got better, often times someone eventually triggered the legal system and went to jail
There is a separate statute of stalking that smaller departments are not that good handling but larger departments will have Detectives assigned just to those cases. With enough evidence a case can be made for stalking without someone ever laying a finger on them. Some examples would be a combination of extensive texting or calling after being told not to and no contact from the victim is happening. Them showing up at a workplace, or suddenly appearing in public places everywhere the victim is. I used to work those cases for a couple years and while difficult to make a case (as it should be because sometimes people just happen to be in the same place) arrests were made. One that stands out while I'm writing this was a guy who had a voice that sounded just like Elvis. He wasn't trying to he just had that voice. He would leave 80 voice mails a day on this womans phone and while he did numerous other things that were not funny and he eventually got arrested, it was kind of amusing hearing Elvis begging her to call, he's sorry, he loves her, then the next call is all profanity, the next is sweet..