As we noted in the Morning Roundup, D.C. Mayor Adrian Fenty and Police Chief Cathy Lanier are making their way to the 1400 block of Columbia Rd. NW right now in order to announce that an arrest has been made in the killing of 9-year-old Oscar Fuentes. The Post says the man who was arrested is Josue Pena, 26, who was taken into custody in Hyattsville just before 6 a.m. this morning. No more details on the arrest are available just yet, but check back in after the 10 a.m. press conference.