More than three years after the attacks of Sept. 11, 2001, infighting between federal agencies has so slowed efforts to unify the government’s various systems for identifying fingerprints that most visitors to the United States are still not fully screened, Justice Department investigators said in a report issued on Wednesday.Glenn A. Fine, the Justice Department’s inspector general, warned in the 110-page report, his fourth report on the problem, that the bureaucratic disagreement “creates a risk that a terrorist could enter the country undetected.” In addition, criminal aliens – people who committed violent crimes in other nations – are often not identified before they enter the United States, the report said.Full Story