The most common and most likely answer to this crossword clue is the 5 letter word CASED
I've seen this crossword clue in The Guardian
C
A
S
E
D
More clues leading to the result CASED
- Covered, having undergone a criminal check
- Like some packages with crumpled marks about to be dumped
- Checked out in days, with luggage
- Boxed in when Chancellor’s outside department
- Checked out suit with daughter
- Fourth law suit, as viewed by robber, potentially
- Prepared to steal from box with diamonds
- Examined the fourth victim?
- Checked out luggage on Delta
- Given protective covering, like some joints are?
Buddy explains!

The straight part
We know that "Prepared to steal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case prepared to steal = cased.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 CASED mean?
CASED verb- To propose hypothetical cases.
- To place (an item or items of manufacture) into a box, as in preparation for shipment.
- To cover or protect with, or as if with, a case; to enclose.
- To survey (a building or other location) surreptitiously, as in preparation for a robbery.
- Having a case or covering; encased or clad.