A new investigation into the murders of three Marines by a teenager on a forward operating base in Afghanistan shows gaps in security ahead of the attack. The investigation, completed in October at the request of Marine Corps Staff Director Maj. Gen. Michael Regner, also appears to contradict claims that the murders were linked to a corrupt Afghan police chief with alleged ties to insurgents.

The 18-page inquiry comes more than two years after the Aug. 10, 2012, attack that killed Lance Cpl. Greg Buckley Jr., Cpl. Richard Rivera and Staff Sgt. Scott Dickinson at Forward Operating Base Delhi in Afghanistan's Garmser district. Reviewed by Marine Corps Times reviewed the report, which includes interview summaries from of 18 Marine Corps and other military officials who witnessed the attack or participated in the response. Most of the Marine sources were members of Police Adviser Team-District Garmser, which oversaw an Afghan district police headquarters compound adjacent to FOB orward Operating BaseDelhi, and from 3rd Battalion, 8th Marines, which was responsible for the FOB.

According to a memo from Regner to the investigating officer, whose name was redacted, the probe was initiated in August. 2014 to "ensure sufficient information is available to brief our … Gold Star families about the loss of their loved ones."

It asks for an overview of the operating environment at FOB Delhi, where the attacks occurred, details of the circumstances surrounding the attack, and discussion of the actions taken related to the prosecution of Ainuddin Khudairaham, the attacker.

The memo is dated Aug. 7, 2014, just days after news broke that Khudairaham had been tried as a juvenile in Afghanistan and sentenced to just seven years, six months in prison. Family mMembers of one of the murdered Marines, Lance Cpl. Greg Buckley's Jr., family told Marine Corps Times in July they found out about the trial only after it had taken place and felt "betrayed" by the alleged lack of communication from the Marine Corps about the proceedings.

The report reveals that a new district chief of police, Sarwar Jan, had arrived at FOB Delhi on July 22, 2012, less than three weeks before the shootings. Khudairaham arrived separately three days later to work for Jan as a personal assistant. The report says he was pursuing training to join the Afghan National Police.

Sarwar Jan, who had previously been fired in another district for beating locals who didn't pay illegal taxes he imposed, has been described in media reports, correspondence and a book by military author Bing West as a suspected child molester who operated illegal checkpoints and sold weapons to the enemy. The report, however, contained a much milder assessment.

The report said Jan had a "previous reputation for accepting and or receiving money in exchange for personal favors" that was known to Marine leaders at the FOB, but the Marine police adviser team had never found any evidence of human trafficking or child sexual abuse, despite close monitoring of the Afghan compound. Jan was relieved in the wake of the attacks, but he resurfaced at Lashkar Gah in Helmand province as an Afghan National Police company commander, where he was interviewed by Naval Criminal Investigative Service agents in January. 2014, according to the report.

Though members of the Buckley family and others have contended that claimed Khudairaham carried out the attack at the bidding of his boss, Jan, the report does not substantiate a link between Jan and the murders.

Khudairaham, believed by some to be Jan's "chai boy" and subject of his sexual abuse, was young but no more so than many of the Afghan police in the compound, according to the report said. Khudairaham's age is the subject of dispute: while reports from his detention estimate his age at 19, a U.S. bone density examination determined he was 17 at the time of the attack. A panel of three Afghan doctors would conclude in 2014 that he was between 17 and 18 when the shootings took place, resulting in his trial as a juvenile.

On the afternoon of the murders, Marine witnesses recalled noticing that Khudairaham appeared freshly showered and smelling of cologne, an occurrence they called "odd" and "weird," though they allowed that Afghans often did things that Marines considered strange.

The attack occurred had come toward the end of a quiet deployment in which Marines had not had a firefight in nearly a year. According to the report, the police adviser team was focused on building trust and relationships with their Afghan counterparts. Both of those factors affected the security situation on the day of the shootings.

Because posting armed "guardian angels" near areas where Marines and Afghans interacted had been perceived as an offense by Afghan police, Marine officials had resorted to a more subtle overwatch. Sometimes, an armed Marine would take an apparent smoke break in the vicinity of a joint meal or meeting to act as a guard without being detected.

Some called the FOB Delhi gym on the Afghan district police headquarters compound one of the less secure parts of the base. Marines were allowed to work out in the open-air facility, but its location offered only partial visibility to the Marine guard at the FOB's entry point, and Afghans were able to look in at the Marines working out. The day of the attack, there was no guardian angel in the gym. Several Marines were wearing had headphones in, which was allowed, but resulted in a "loss of situational awareness," ahead of the killings, the report said. Only one of the seven Marines inside the facility had a weapon, and he was unable to reach it when Khudairaham opened fire.

The youth had entered the police compound, obtained keys for the shower facility, and then, 30 minutes later, attacked the Marines with a loaded AK-47 inadvertently left unattended by an ANP officer.

After an initial volley of bullets, Khudairaham moved through the gym to ascend the adjacent northeast tower. He was confronted and disarmed by Afghan police and then captured by a Marine quick reaction force after trying to escape.

But the damage was done: three Marines -- Buckley, Cpl. Richard Rivera, and Staff Sgt. Scott Dickinson -- had been fatally shot. A fourth and another Marine was wounded.

The report does not attempt to assign blame for circumstances surrounding the attack, but it does add that the police adviser team made significant changes to their protocol after it happened. While working at the Afghan police compound, Marines thereafter were always armed and wore full protective gear and posted an overt guardian angel guard.

But no recommendations were made, and the report investigation concluded that no further investigation was warranted.

The probe also carries no mention of an emailed warning sent a few weeks prior from a civil affairs officer, Marine Maj. Jason Brezler, regarding Jan. Though Brezler's decision to send a classified file about Jan through his personal email account would result in a board recommendation that he be discharged, members of the Buckley family have claimed his warning, if heeded, could have saved the life of their son and the other Marines. The report also indicates the recipient of the email, Maj. Brian Donlon, an operations officer for 3/8rd Battalion, 8th Marines, was not interviewed as part of the investigation.

A spokesman for Marine Corps Headquarters, Lt. Col. John Caldwell, confirmed the report was authentic and said no Marine officials had faced repercussions as a result of the circumstances surrounding the shootings.

""This inquiry discovered no evidence to warrant administrative or disciplinary action against any Marine associated with this unit," he said in an email.

The Buckley family, who has sued the Marine Corps in federal court for information about the insider attack, said through their attorney, Michael Bowe, that they were unsatisfied with the report.

"After stonewalling the Buckley family for over two years, the Marine Corps has now leaked a skewed, incomplete, and inaccurate report commissioned just months ago. But it has still not produced all the legally required documents," Bowe said in a statement. [The report] is most remarkable in the questions it avoids entirely: Why was a known pedophile, terrorist, and corrupt Afghan official allowed to bring unknown boys onto the base; why was a warning about that threat ignored; and why has no one been held accountable for the three Marines who were murdered because of those lapses."

Marine Corps Times obtained the report from an independent source, not from Marine Corps officials.

An attorney for Brezler, who is also suing the Marine Corps in federal court over the recommendation he be discharged, called the report a "whitewash."

"An outside entity such as the FBI should investigate what happened at FOB Delhi, and how some senior Marine officers withheld information from Gold Star families and retaliated against whistle​-blowers to cover up those events," said Kevin Carroll, who represents Brezler pro bono.

The Buckley and Brezler cases are pending in New York's Eastern District.