Another witness, an eight-year-old girl called Noorbinak, said a gunman shot her family's dog before shooting her father in the foot and dragging her mother by the hair.
When her father screamed, he was shot dead, before the gunman shot Noorbinak in the leg.
She said: 'One man entered the room and the others were standing in the yard, holding lights.'
The brother of another victim claimed that his nephews and nieces saw numerous soldiers involved in the assault, all wearing headlamps and with lights strapped to the ends of their guns.
He said: 'They donâ€™t know whether there were 15 or 20, however many there were.'
Afghan President Hamid Karzai has appointed General Sher Mohammad Karimi to investigate persistent claims by locals that Bales did not act alone - and that he even had the support of U.S. helicopters.
General Karimi told Hakim: 'What they claim is that there were boot prints in the area, in some area they see the kneeling position of three, four individuals, and also they claim that the helicopters were there to support the operations.
'I told them the helicopters were used when the guy went missing when they were searching for him. They said: "No, the noise of the helicopters were from the very beginning when the shooting started."
'So, that means there were many Americans who were supporting this issue that were doing this deliberately it is not an individual. So, that is the claim of the people.'
It is also claimed that an Afghan guard alerted the U.S. authorities to the unusual behaviour of an American soldier that night after spotting him entering Camp Balambai at 1.30am, shortly after the first killings in Alkozai village.
Despite the warning, Bales is said to have remained at the camp for an hour before setting off for the village of Najiban to carry out more killings.
Bales suffered a traumatic incident during his second tour in Iraq that triggered 'tremendous depression,' his lawyer said on Wednesday.
John Browne expects the issue to become a focal point in the case against the army sergeant.
But he said he could not discuss the details of the matter because it remains classified.
Mr Browne said: 'It caused him tremendous depression and anxiety.'
The lawyer previously said Bales experienced other major dangers in his deployments, including a serious foot injury and head trauma.
In addition, a fellow soldier's leg had been blown off days before the Afghanistan massacre, he said.
A defence team is now in Afghanistan to collect evidence and interview other U.S. soldiers who knew Bales.
Mr Browne, who is not part of the team in Afghanistan, said: 'Everyone they've spoken to in the military has nothing but amazingly positive things to say about him.'
Due to security concerns, Mr Browne doesn't think the team will visit the villages where the killings occurred. The investigators are likely to stay in Afghanistan for a few more weeks.
Mr Browne questioned the U.S. government's case against Bales, noting there is no preserved crime scene to assess.
He said: 'It's going to be a difficult case for the prosecution to prove. There's no "CSI" information. There's no DNA that I know of. There's no ballistics that I know of.'
Bales has indicated that he had no recollection of prescription drugs he may have been taking before the shooting - something the attorney took as an indicator of larger memory problems.
The lawyer also said his client has a sketchy memory of the night of the shootings.
In a separate interview with The Washington Post, Mr Browne said that Bales remembered the smell of gunfire and of human bodies but not much more.
Mr Browne added his client reported suffering from nightmares, flashbacks of war scenes and persistent headaches after his multiple combat tours.
Bales told his legal team that he has long woken up with night sweats and often replays memories of a grisly scene in Iraq that he and his infantry company witnessed several years ago.
The lawyer stressed that Bales did not confess and seemed surprised when his weapon was taken away, the newspaper reported.
U.S. military officials said Bales was drinking on a southern Afghanistan base on March 11 before creeping away to two villages at night, shooting his victims and setting many of them on fire. Nine were children.
Bales has had incidents involving alcohol and violence in the past.
In 2002, he was arrested for a drunken assault of a security guard at a Tacoma, Washington, casino. That charge was dismissed after Bales completed 20 hours of anger management training.
In 2008, a couple accused an intoxicated Bales of grabbing a woman's hand and thrusting it toward his crotch before kicking and punching the woman's boyfriend, according to a police report. Prosecutors declined to pursue that case.