Police Headquarters for the country is : Palacio de la Policia Nacional, Leopoldo Navarro esquina Avenida Mexico, Santo Domingo, R.D. tele:809-221-2151 (they also have a jail/holding area here).
Which jail are you looking for??
One primary jail is Cuidad Nueva located by the Palacio Justicia in Santo Domingo, and nearby to Clinican Abreu on Ave. Independencia. Other choices are Najayo or La Victoria prisons, depending on how important the person is, or the seriousness of the actions committed (or thought to have been committed) by that person.