The DMUs ALn DAP, according to some sources also known as ALn 663 DAP, are Italian railway rolling stock with particular features. They derived from the ALn 663 of Ferrovie dello Stato, from which they took their outward appearance.
The abbreviation DAP is the acronym for Dipartimento Amministrazione Penitenziaria (Penitentiary Administration Department) and the DMUs are operated by Ferrovie dello Stato on behalf of the Ministry of Grace and Justice, who bought them in 1996 for the transportation of prisoners.
Internally, there are cells with minimum services and a compartment service for agents. For some years, the ALn DAP traveled according to a predetermined schedule with weekly shifts. The entry and exit of prisoners from the rolling stock occurred in particular areas of the stations, obviously under strict control of the police.
Granted for their conduct to a group of drivers of Genio Ferrovieri, they have been deactivated since 2005, to serve in the Locomotive Depot of Bologna Centrale.