The most common and most likely answer to this crossword clue is the 4 plus 9 letter word UGLY CUSTOMERS
U
G
L
Y
C
U
S
T
O
M
E
R
S
More clues leading to the result UGLY CUSTOMERS
Buddy explains!
The straight part
We know that "bad people" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bad people = ugly customers.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.