‘‘I saw someone standing in the entrance to the tent shooting at all of us,’’ said the sergeant who had been hit in the leg by shrapnel. ‘‘I put my head down. I believe I heard five or six rounds fired, and then the shooting stopped.’’

Maj. Keith Walters, who was in the tent and suffered a severe leg wound from the M16 fire, said that by the time the gunman vanished it was too late.

‘‘As the firing stopped, I remember yelling out to hold fire as I knew we had friendly U.S. and Afghan forces somewhere in the compound and that by then they would probably be approaching the tent. We did not return a single shot,’’ Walters wrote in an email to investigators three weeks later from his hospital bed in Washington, where he underwent surgery.

Walters’ unit, the Army’s 4th Infantry Division, denied an AP request to interview Walters, saying the matter was too sensitive; later it said Walters had decided on his own not to be interviewed.

Lawrence apparently died instantly of his head wound. Russell was declared dead a short time later at a nearby helicopter landing zone as colleagues prepared to evacuate him and three seriously wounded soldiers to medical facilities at Kandahar Air Field.

Four other soldiers were wounded less severely.

The killers escaped — apparently with inside help. They remain at large.

Gen. Jallaad Rahimi, who was the chief military prosecutor in Kandahar at the time, told the AP in a recent interview that the father and brother of Sgt. Enayut, plus three of his fellow soldiers, are in detention. The three soldiers are not accused of shooting anyone but are charged with neglecting their duties or assisting Enayut, Rahimi said. For example, the rocket-propelled grenade fired by Enayut was assigned to a member of his unit who told investigators that Enayut had taken it from him that evening when he was not looking, Rahimi said.

Rahimi said two of the detained soldiers are accused of helping Enayut escape the compound.

Enayut’s father and brother were arrested after authorities found evidence at their home that Enayut had been in contact with insurgents, Rahimi said. The brother and the father knew about this contact, Rahimi said, but didn’t tell authorities and may have covered up for Enayut. The U.S. investigation found no links to insurgents.

Enayut, 23 at the time of the shooting, joined the Afghan army in 2006. An expert in disarming bombs, he had a history of going AWOL and receiving no punishment for it. U.S. investigators found that he had slipped away for an unauthorized visit to Pakistan just weeks before the attack.

Investigators were unable to pin down identifying information about the other shooter, although it appeared he also was a soldier and was probably a member of Enayut’s unit, the 4th Battalion, 1st Brigade, 205th Corps. LeVan said both wore Afghan army uniforms in the attack.

In a two-sentence statement the next day, the U.S.-led military command in Kabul said two service members had been killed in an ‘‘insurgent attack.’’ A day later, in identifying Lawrence and Russell as the casualties, the Pentagon reported that ‘‘enemy forces’’ killed them.

The Army’s investigation records show that U.S. officials in Afghanistan were told immediately after the assault that it was perpetrated by one or more Afghan soldiers — not insurgents.

‘‘Yes, we know the shooter,’’ the Afghan army liaison officer told Lt. Col. John Cook, the commander of Lawrence’s and Russell’s unit, after being summoned back to the compound just moments after the killings. The Afghan officer named Enayut without hesitation.

Asked why its Oct. 9 report was never corrected, the international military command in Kabul said it knew that at least one of the shooters was wearing an Afghan army uniform, ‘‘but as that information was unconfirmed, a correction to the original (press) release was not appropriate.’’

In April the AP was alerted to the attack’s true circumstances by an American soldier who knew the real story. The U.S. military in Kabul acknowledged to the AP in May that it had added the incident to its 2011 list of insider attacks. But it refused to provide any details of what happened.