armed robbery; armed robber
Refers to both the crime and the person committing it. Context determines whether it means the act or the perpetrator.
An armed robber attacked the bank.
A man was arrested on suspicion of armed robbery.
強盗 is a general term for robbery or robber, while 武装強盗 specifies that the perpetrator is armed.
Compound of 武装 (armed) and 強盗 (robbery/robber).