I assume you want to tap from fuse block F-02 (between the driver's foot and the door), rather than running another wire through the firewall.
The supply bus for F-02 F1 through F7, i.e. the vertical bank of 7 fuses at the upper left, is powered directly from the battery, unswitched. F2 is the door locks, which might be a good one from which to tap an always-live 12V to USB converter for your security camera.
Give the converter its own 5 A fuse.
Do note that this is a good way to run a battery flat if you leave the car parked for a long time.