noun, feminine/a.ʁɛs.ta.sjɔ̃/plural: arrestations
arrest (“The act of arresting a criminal, suspect, etc.”)
Related: en état d'arrestation
From Middle French arrestation. Equivalent to arrêter + -ation. The noun, being of a more formal register, was standardised with a Latinate pronunciation, while the verb has the popular form with loss of preconsonantal s.