The Justice Department is maintaining the right to continue the warrantless tracking of suspects with GPS, despite a Supreme Court ruling that doing so is illegal. The high court ruled in January that police monitoring through attaching a GPS to a suspect’s vehicle is a constitutionally protected search. The ruling marked a defeat for the Obama administration, which had fought to overturn an appeals court ruling that warrants are required. But in court arguments Thursday, the Justice Department said the warrantless tracking remains legal because the Supreme Court did not specifically state that a search warrant is required in other cases.