The most common and most likely answer to this crossword clue is the 5 letter word THUGS
I've seen this crossword clue in The Guardian
T
H
U
G
S
Buddy explains!
The straight part
We know that "Their victims got it in the neck" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case their victims got it in the neck = thugs.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.
What does THUGS mean?
THUGS noun- Someone with an intimidating and unseemly appearance and mannerisms, who treats others violently and roughly, often for hire.
- One of a band of assassins formerly active in northern India who worshipped Kali and offered their victims to her.
- In gardening, an over-vigorous plant that spreads and dominates the flowerbed.
- A punk; a hoodlum; a hooligan.