This is the 2142nd most frequent Russian word.
арестовали
"Арестовали" means "arrested."
Here, 'арестовали' is used to describe an action performed by the police, signifying a legal detainment.
Вчера полиция арестовала подозреваемого.
Yesterday, the police arrested the suspect.
In this sentence, 'арестовали' explains the reason for the action, namely a specific crime.
Его арестовали за ограбление банка.
He was arrested for robbing a bank.
This usage illustrates that the verb 'арестовали' can denote the act of arresting multiple individuals.