General comment.
I think the police are in general ill equipped to deal with disputes between neighbors, coworkers, tenants and landlords, domestic disputes, clients and service providers, with dangerous or mentally ill family, etc. In the last couple of decades there has been effort in many jurisdictions put into figuring out how to keep women and children safe in domestic disputes, but I’m not sure the lessons learned there translate to other kinds of interpersonal conflict.
Police are trained for and reasonably good at clear cut and obvious law breaking or violence, the speeding driver or bank robber or bar brawl, where the “perpetrator” is obvious.
I think they tend to be more cautious when they get called into ongoing disputes between people who know each other. I don’t think the average policeman is going to be able to do much with a claim someone is stalking you online or posting that they have a gun. Especially if both parties are making competing calls to 911 or other emergency services.
My guess is that if you have that kind of dispute erupting, you might be better off going for restraining orders, eviction orders, whatever applies in your jurisdiction, with the help of a lawyer. Of course these approaches take time.
By all accounts, the relationship here went sour fast, within a week. Did we ever find out what triggered it?