What biometric data is better to use for identification?

Question

CCTV

What biometric data is better to use for identification (restriction - this data must be obtained at home, for example, using a webcam or microphone)?

Answer 1

At home, methods through a microphone or webcam are too unstable.
In the microphone - noise + background environment
In the webcam as well.
Can you voice why such a hemorrhoid method is required?
I don't have a webcam or microphone.

Answer 2

stool analysis =D. everything else is easily faked