This is the 2016th most frequent Dutch word.
criminele
"Criminele" means "criminal" in English.
Here, 'criminele' is used as an adjective to describe the nature of the activities, indicating they are related to crime.
De criminele activiteiten worden door de politie onderzocht.
The criminal activities are being investigated by the police.
In this sentence, 'criminele' qualifies the noun 'organisatie', suggesting that the organization is involved in illegal activities.
Hij behoort tot een criminele organisatie.
He belongs to a criminal organization.
Here, 'criminele' describes the attacks, specifying their unlawful and dangerous nature.