The last month's strange things have happened in my mother's apartment.

It started out a while back after she bought new underwear (panties) because her old ones were missing. She knew she threw away some of them, so her first thought was just that she had managed to throw more of them away than she was supposed to.

But some weeks later, she called me and was kinda frightened because now, some of her new underwear was missing too.
I told her to check if they were inside the holes in the washing machine, but even though she searched the whole apartment they were nowhere to be found.

Some more weeks passed, and my grandmother got really sick. @xtetrahedron and I moved into my grandmother's apartment to help clean it up and make it ready for sale.
This apartment we live in now is in the same building as my mother's.

About 3 weeks after, my mother asked me a very serious question.

"Emilie, I know this is a weird question but is the person who keeps stealing my underwear you?"

I had to make it very clear for her that I do not use her size at all, and that I was living in the cabin when the two first thefts happened.
She said she knew it wasn't me, but that she had to ask because she can't wrap her head around what's happening, and is starting to feel a little crazy.

At this point, around 9 panties are missing in total.

My mother recently got a puppy that takes up a lot of her attention, and she admits running out with him when he pees inside, without locking the door a few times. She even went into my grandmother's apartment without locking the door.

But something makes us wonder:

• Things are missing from the laundry basket, drawer and drying rack. So the person coming in here must be pretty familiar with where things are stored in the apartment.

• She goes out for such short periods at a time that the person must be very brave to go into the apartment.

• She heard the door close itself some days ago while she was sitting at the balcony, only minutes after returning home to her apartment: Was someone hiding, and snook out once he or she was out of my mother's line of sight?

• A small and not so importantly amount of money was missing from the apartment yesterday, did someone take them?

• Does someone creepy have the keys to her apartment?

So now we got her a surveillance camera!

We are all quite excited and a little scared to see what's actually going on in there.
It has a motion sensor and gives her a notification on her phone when someone moves in front of the camera while she's not there

So my last question to you is: What do you think?

Is my mother going crazy or is someone stealing her underwear?