People jumping to a possible dementia diagnosis or berating the OP for being unkind are obviously lucky enough to have had a mother who truly loved them. Unfortunately there are many of us who weren't so lucky. It would, however, have been helpful for the OP to have explained initially that there was a backstory, particularly as it happens a lot here that people don't read the rest of the thread before responding.
OP when I read your initial post I had a feeling it might be a situation like my "mother" who has always used the phone as a weapon. So I wasn't surprised to read your later post
My mother has been hard work since I was a young child. She hated having children and told me that she regretted having children. She never once showed me any love. Ever. Just shouted and screamed at me since the day i was born.
She is not going to change. She is the centre of her universe and you only fit in that universe so long as you behave. Not answering her call is not behaving, so therefore you had to be punished. Calling the police was an extreme move on her part so that you would know in future to behave and to answer her calls. She will not be ignored!!
As you cannot change her, you can only change how you respond to her. I'm happily a couple of years no contact with my narcissistic mother, whose covert abuse went unseen by everyone all my life, I didn't even understand it was her rather than me until a situation over the phone resulted in me seeking therapy.
I was away for the weekend and told her I was turning my phone off. When I came back she started spouting off at me. I didn't rise to her bait and she kept escalating and escalating. Finally she told me if I was a proper mother she would have a better relationship with her grandchildren. (Who she never babysat or loved or helped me with, but constantly criticised them as children and me as a mother, yet because of my special training I stayed).
The situation was never resolved. She left me a voicemail saying she didn't know why I wanted an apology but she was sorry. She wrote me a letter calling me a liar and telling me to leave her alone. She has alienated all her side of the family, bar 1 person, from me. She "cries" if someone asks about me but doesn't tell them she told me to leave her alone or about the rest of her behaviour.
Through therapy I now understand that I have been emotionally neglected and suffering narcissistic abuse my whole life. It has been hard to get my head around this, but now I hold my head up high and if anyone asks about my family I give them an honest but unemotional answer. It has been amazing how many people have then opened up to me about abusive behaviour in their families. My life is so much more peaceful without her in it. I have blocked all those who supported her and didn't even contact me to see how I was doing and would suggest you consider the same, especially given she has a history of dispatching "flying monkeys" to get you back in line.
I posted some links on another thread recently to Instagram accounts and podcasts that I've found really helpful, I'll have a look later and see if I can find them.