A late night call

So, the other night, I was lying in bed and woke up the my Mum's voice outside my bedroom, saying, "Yes, can I have the police please?" Now baring in mind, this was approximately 12 o'clock at night, I started to worry.
On jumping out of bed, I opened my door to find my Mum, her shaking hands wiping a tear away from her eye, on the phone. Now my Mum doesn't cry much, she believes in staying strong for my Brother; Max and Me. She put down the phone and was anxiously peeking out the window, through a small gap between the curtains.
After asking several times what was happening, my Brother came out of his room, also questioning what was going on. My Mum replied with " I had to call the Police. Someone, a man, just called me and told me he was outside in the garden watching me through the window. He said he was coming to get me, he could see me and was coming to get me."
Now, my first reaction, like i'm sure many people's reaction was when listening to this story, was that it was a prank call, a joke, a cruel joke. But my Mum isn't stupid, and I could see the genuine fear in her eyes and the turned corners of her mouth. But who would do such a thing? This was more that a joke, it was an act of selfishness and attempt to scare.
Moments later, the Police arrived and searched the garden before knocking on the door. My Mum went downstairs and told us to stay upstairs. When she had invited the officers into the living room, Max and I waited on the stairs, intently listening to what they had to say. They were asking her all sorts of questions like "Was there any background noise?" and "Did they have an accent?" These were all pretty average, boring questions and I was about to give up and go back to bed, not hearing anything of interest at this point, until i hear "Could there be an ex husband involved?" Until this point, I didn't think of my Dad. But when it was mentioned, I knew he was capable of doing such a thing after events that have happened in the past.
Two weeks later, and I still don't know who it is, it could be my Dad; which wouldn't be clever with his history with the Police as well as the fact that it's taken him forever to get a job and he pays nothing for us as it is.
I'm not too sure how to conclude this, but I guess what I'll say is no matter what happens in life, there's always someone there for you, and for me, that one person is my Mum.