Security cameras on front door

[Etain0]

Hi, I want to set up a security camera on my apartment front door to see who enters, as I have found guests renting for 3 for example and then having more to stay. Which is totally not acceptable and also can cause me serious problems with the neighbors.

So What camera can I install to see who enters my garment?

I have a security alarm system, but that does not monitor who enters and leaves.

Any help is appreciated, thanks 

[Annie1372]

@Etain0 

Security camera are different depending of which country around the globe you are.

i guess you would find better answer at you closest electronic shop or even on your local Google search