Input (grade 13): The police made a serious mistake by locking up over 20 alleged supporters of the Kelly gang between the third of January 1879 and 22 April 1879 under the Felons Apprehension Act 1878.
Output (grade 12): The police locked up over 20 possible supporters of the Kelly gang between January 1879 and April 1879 under the Felons Apprehension Act 1878.