By Paul Cruickshank and Tim Lister
More than three months after the attack on the U.S. Consulate in Benghazi, Libya, not a single person has been charged in connection with the assault.
Most, if not all, of those questioned in Libya since the attack have been released.
A Libyan source with knowledge of the investigation, who did not want to be identified because of the sensitivities involved in the probe, told CNN there are indications that the perpetrators of the attack came from beyond the Benghazi area and slipped away immediately afterward. The source says it is possible the attackers came from the city of Derna or surrounding areas, about 120 miles (200 km) to the east, which remains a stronghold of militant Islamist and jihadist groups.
The September 11 attack killed four Americans, including Chris Stevens, the U.S. ambassador to Libya. The State Department's independent report on security lapses in Benghazi did not focus on who was responsible as part of its mandate, review leader Ambassador Thomas Pickering said Wednesday, but the FBI continues to investigate.
Militant Islamist and jihadist groups are now flourishing in eastern Libya, the source says, and are too strong for the government to "put back in the box." Independent militias like Libyan Shield - which includes militant Islamists among its members - continue to dominate in Benghazi, and the government's security forces and judiciary are toothless.
Sources monitoring the security situation in eastern Libya say that if anything, it has worsened since the attack on the consulate, with a series of assassinations and attempted assassinations of security officials. Islamist militants are blamed for many of these attacks.
One of the officials killed was Faraj Mohammed el-Drissi. He was gunned down in Benghazi in late November. Drissi had been in charge of the city's security for just one month. Of his three alleged assailants, one was subsequently arrested, the Libyan source said.
On Sunday, there was a major attack on the security headquarters in Benghazi - apparently in an effort to try to free the arrested man. The attack included the use of at least one rocket-propelled grenade, and a lengthy sun battle followed. The source told CNN four police officers were killed, but the attackers eventually fled without being able to free the man. The source says that according to local officials, the attack was launched because the detainee had begun to talk about who was behind the assassination - and had implicated a former Guantanamo Bay detainee.
That man is Sufian bin Qumu, who earlier this year was believed to be operating a camp in a remote area outside Derna. His detainee assessment at the prison camp described him as having a "long-term association with Islamist extremist Jihad and members of al Qaeda and other extremist groups."
While no evidence has emerged that bin Qumu had any direct role in the Benghazi attack, Libyan intelligence officials say he is still active in the Derna area, where militants are passing through his training camps - including some former members of the Libyan Islamist Fighting Group (LIFG).
"The main question is, to what extent is he part of al Qaeda?" asked the Libyan source.
In an interview with a local media outlet earlier this year, bin Qumu made clear that the time he spent in U.S. custody had left him embittered toward the United States, but he denied he was a supporter of violence.
Bin Qumu is thought to be setting himself up as the "emir" of a new jihadist group in eastern Libya, promoting his background as a Guantanamo detainee and former driver for Osama bin Laden's organization in Sudan in the 1990s. Now in his early 50s, he is said to be promoting his long experience in jihad to recruit followers.
That has involved some embellishment of his record, according to sources familiar with his background. Bin Qumu was never among the leadership of the LIFG. He was known as a "tough guy," says one source, but never assessed by his peers as having the skill set necessary to take on a military command position. The source also points out that bin Qumu was a driver for one of bin Laden's companies - not his terrorist group. He had a long criminal record before embracing jihad and being a relatively late arrival to LIFG ranks in Afghanistan around 1993.
One man who had allegedly been running a militant training camp in eastern Libya last year is under arrest, but not in Libya. Muhammed Jamal Abu Ahmad - a former member of Egyptian Islamic Jihad - was detained in Cairo earlier this month. Analysts believe he had ambitions to create a new terrorist network in Egypt and across North Africa. He remains in custody but has not been charged.
According to Libyan intelligence officials, Jamal was suspected of setting up a camp south of Derna, where foreign jihadists as well as Libyans were being trained.
A former Egyptian jihadist told CNN Jamal was a mid-level operative in Ayman al Zawahiri's Egyptian Islamic Jihad in the 1990s. He spent time in Afghanistan and Sudan before being imprisoned in Egypt in the early 2000s. After being released in the wake of President Hosni Mubarak's downfall, Jamal likely sought to reconnect with his former boss, according to another former jihadist.
The city of Derna and surrounding area has for years been a recruiting ground for al Qaeda and its affiliates. In a 2008 diplomatic cable, Chris Stevens described his visit to the area when he was a diplomat posted at the U.S. Embassy in Tripoli. He outlined how high youth unemployment, discrimination by the Gadhafi regime and the influence of veteran Libyan jihadists from Afghanistan all played a role in radicalizing a new generation.
He said the area was "a wellspring of Libyan foreign fighters" for al Qaeda in Iraq - fighters who may have had a role in his death four years later.