Green’s Dictionary of Slang

dropped adj.¹

arrested.

1904		‘Number 1500’ Life In Sing Sing 248: Dropped. Arrested.
1924		G. Henderson Keys to Crookdom 403: Dropped. Arrested.
1949		Monteleone Criminal Sl. (rev. edn).
1951		D. Dressler Parole Chief 79: big jake is wintering in Joliet. Dropped in Chi.