CHICAGO (WLS) -- A federal agent from the U.S. Department of Housing and Urban Development shot and killed a masked criminal suspect Thursday morning in far north suburban Zion, but the incident is still cloaked in secrecy.For nearly 12 hours, authorities in charge of the investigation released no information at all - not even the name of the U.S. agency the law enforcement officer worked for.The man shot to death was allegedly pointing a gun at the federal officer who was in a car at the intersection of Ezekiel Avenue and 30th Street in Zion. The man who was shot was in his late teens or early 20s, according to police sources. An autopsy in Lake County is scheduled for Friday.Illinois State Police, who are overseeing the investigation of the shooting by the federal agent, have not answered any questions about what happened or why or provided the names of those involved. Only after repeated inquiries by the ABC7 I-Team, did state police officials late Thursday afternoon say that the federal agent worked for HUD. One source familiar with the department said that only agents with HUD's Office of Inspector General are armed. That office works fraud investigations and corruption cases, among other criminal investigations related to federal housing programs.Zion police, who emphasized in a statement that it was not one of their officers who shot and killed the suspect, said that a male armed with a handgun and several other people approached the vehicle.After the suspect, who was wearing a bandana over part of his face, "displayed the handgun to the agent," police said the federal agent shot him through the vehicle's window.According to Zion police, the rest of the group then ran away.The suspect was dead at the scene, according to Zion paramedics. The agent was taken to an undisclosed hospital and his condition has not been released.HUD officials in Washington, DC did not immediately respond to requests for information, including questions about why the agent was said to be on duty - but alone - on a Zion residential street at 6 a.m.Authorities have not said whether this was a robbery gone bad, an attempted carjacking or related to an official HUD investigation.