A) You don't judge them.
B) By looks.
C) By personality.
D) Looks and Personality.
E) Beliefs.
F) Meet them more than once to judge them.
G) What they're wearing.
H) Who they're with/associate with.
I) Other
I take in everything about them that I can. Age, model of car, looks, if their hair is dyed or not, if they're right handed or left, etc. etc. etc. But not to make a decision about them as a person... Just to get a good police description.