Expert having caught American in charge (6)
I believe the answer is:
accuse
'charge' is the definition.
('accuse' can be a synonym of 'charge')
'expert having caught american' is the wordplay.
'expert' becomes 'ace' (ace is a kind of expert**).
'having' means one lot of letters goes inside another.
'caught' becomes 'c' (cricket abbreviation).
'american' becomes 'us'.
'c'+'us'='cus'
'ace' enclosing 'cus' is 'ACCUSE'.
'in' is the link.
(Other definitions for accuse that I've seen before include "Bring a charge" , "Charge with, indict" , "Impeach" , "make charges" , "Lay blame for wrongdoing on named person" .)