Crime squad at first expecting to receive boost (11)
I believe the answer is:
shoplifting
'crime' is the definition.
(shoplifting is a kind of crime)
'squad at first expecting to receive boost' is the wordplay.
'at first' says to take the initial letters.
'expecting' becomes 'hoping' ('hope' can be a synonym of 'expect').
'to receive' indicates putting letters inside.
'boost' becomes 'lift' (both can mean to steal).
The initial letter of 'squad' is 's'.
'hoping' going around 'lift' is 'hoplifting'.
's'+'hoplifting'='SHOPLIFTING'
(Other definitions for shoplifting that I've seen before include "Crime" , "Stealing from stores" .)