Security Concerns Keep FBI From Scene of Ambassador's Murder More than two weeks after militants killed a U.S. ambassador and three other Americans at a diplomatic mission in Libya, FBI investigators have not gone into the city where the attack took place due to security concerns, a federal law enforcement official said today, even if such concerns haven't stopped journalists from operating freely in the same city. In a perfect world, we'd be there. No one is preventing us from going there," said the official, who spoke on the condition of anonymity. Security and safety are the big issues that will dictate when things change. An FBI team arrived in Libya last week to investigate the Sept. 11 assault on an American diplomatic mission in Benghazi that took the lives of Ambassador Chris Stevens, a State Department computer expert and two former U.S. Navy SEALs, but has been waiting for days to actually go to the scene of the attack. PHOTOS: Remembering the Fallen in Libya In the days after the Benghazi assault, reporters were able to walk into the battered buildings that were targeted. CNN obtained a partial diary written by Ambassador Stevens that the network said had been left on the floor at one of the structures and several international broadcast reports appeared to show the buildings completely unsecured. "The site is greatly degraded at this point," the law enforcement official said. What is left? The FBI says on its website that the bureau "plays a critical role" in any response to major incidents abroad involving Americans. The bureau said it works with the State Department and must obtain permission from any host country to conduct a foreign investigation. The FBI declined to comment on the failure to reach the crime scene, which was first reported by CNN, and both the State Department and the White House directed all questions about the investigation to the bureau. The Libyan ambassador to the United Nations, Ibrahim Dabbashi, told ABC News that neither he, the Libyan ambassador to the U.S., nor the Libyan foreign minister had seen the reports about the FBI team having any trouble at all in their investigation and said their American counterparts had not brought it up. "There is full security cooperation between the Libyan authorities and the U.S. authorities," Dabbashi said. All three high-level Libyan officials are in New York for the U.N. General Assembly. Even if the FBI team goes in now, a former FBI agent familiar with foreign crime scenes said it will be extremely difficult to learn anything useful from the scene of a two-week-old crime. "That scene is going to be pretty well picked over," said Chris Swecker, former FBI Assistant Director and FBI on-scene commander in Iraq in 2003. Swecker said it was "shocking" that reporters could walk through the attack site but American investigators haven't been able to get there. "Once [the FBI team is] on the ground, they are very capable, but getting to the crime scene is important," he said. READ: American Killed in Libya Was on Intel Mission to Track Weapons White House Now Calls Incident 'Terrorist Attack' The CNN report came the same day White House Press Secretary Jay Carney told reporters for the first time that President Obama believes the deadly assault was, in fact, a "terrorist attack." The Obama administration had come under fire from Republican lawmakers for what they called inaccurate characterizations of the incident, particularly citing U.S. Ambassador to the United Nations Susan Rice's early description of the attack as being a protest against an anti-Islam film that was "hijacked" by violent actors. For days the administration did not use the phrase "terrorist attack," even as reports emerged suggesting it was a well-coordinated assault that may not have been connected to any demonstrations. National Counterterrorism Center Director Matthew Olsen became the first high-level official to publicly use the term on Sept. 19 and the next day Carney said he believed it was "self-evident" that it was an act of terrorism. President Obama spoke before the United Nations Wednesday and referred to the incident, but did not use the term "terrorism." The same day, Carney told reporters "it is certainly the case that it is our view as an administration, the President's view, that it was a terrorist attack."