By . Associated Press Reporter . PUBLISHED: . 16:41 EST, 24 March 2012 . | . UPDATED: . 16:47 EST, 24 March 2012 . Robert Bales faces the death penalty after being charged with 17 counts of premeditated murder . U.S. investigators believe the U.S. soldier accused of killing 17 Afghan civilians split the slaughter into two episodes, returning to his base after the first attack and later slipping away to kill again. This scenario seems to support the U.S. government's assertion - contested by some Afghans - that the killings were done by one person, since they would have been perpetrated over a longer period of time than assumed when Army Staff Sgt. Robert Bales was detained March 11 outside his base in southern Afghanistan. But it also raises new questions about how Bales, who was formally charged Friday with 17 counts of premeditated murder and other crimes, could have carried out the nighttime attacks without drawing attention from any Americans on the Kandahar province base. The two American officials who disclosed the investigators' finding spoke on condition of anonymity because the politically sensitive probe is ongoing. Many details about the killings, including a possible motive, have not been made public. The documents released by the U.S. military Friday in connection with the murder charges do not include a timeline or a narrative of what is alleged to have happened. Bales, 38, is accused of killing nine Afghan children and eight adults. The bodies were found in Balandi and Alkozai villages - one north and one south of the base, in Kandahar's Panjwai district. Bales, a married father of two, was on his fourth tour of duty in Iraq and had been injured his lawyers say. The charge of premeditated murder means prosecutors believe the massacre was pre planned . Bales also was charged with six counts of attempted murder and six counts of assault in the same case. U.S. investigators now believe that . Bales walked off his base that night and killed several people in one of . the villages, then went back to the base. The American officials, who . are privy to some details of the investigation, said they do not know . why Bales returned, how long he stayed or what he did while there. Tears of grief: An Afghan youth mourns for his relatives, who were allegedly killed by the U.S. service member . Horrific: The bodies of an elderly Afghan man and a child killed in the Alkozai village of Panjwayi district are shown wrapped in blankets . He then slipped off the base a second . time and killed civilians in the second village before again heading . back toward the base. It was while he was returning the second time that . a U.S. military search party spotted him. He is reported to have . surrendered without a struggle. Bales is being held in a military prison at Fort Leavenworth, Kan. There have been previous suggestions . that Bales could have returned to base after the first set of shootings, . but the American officials who spoke to The Associated Press on . Saturday provided the first official disclosure that U.S. investigators . have come to this conclusion. Empty: The couple's Bonney Lake, Washington home was put on the market . for $229,000. Bales' wife and two children have been moved to Joint Base . Lewis McChord in Tacoma . Members of the Afghan delegation . investigating the killings said one Afghan guard working from midnight . to 2 a.m. on March 11 saw a U.S. soldier return to the base around 1:30 . a.m. Another Afghan soldier who replaced the first and worked until 4 . a.m. said he saw a U.S. soldier leave the base at 2:30 a.m. It's unknown . whether the two Afghan guards saw the same U.S. soldier. U.S. officials have said Bales left . the base the first time armed with his 9mm pistol and M-4 rifle, which . was outfitted with a grenade launcher. Bales' civilian attorney, John Henry . Browne, said Friday that he believes the government will have a hard . time proving its case and that his client's mental state will become an . important issue. Browne has said Bales suffered from the stress of . serving four combat tours. The decision to charge Bales with . premeditated murder suggests that prosecutors believe they have . sufficient evidence that he consciously conceived the killings. The maximum punishment for a . premeditated murder conviction is death. The mandatory minimum sentence . is life imprisonment with the chance of parole.
Investigators believe the U.S soldier struck twice - returning to his base between killings .
Bales accused of killing 17 civilians, including nine children, in an Afghan village .
Raises issues of how he could have carried out the attacks without drawing attention from other soldiers .
He is being held at Fort Levenworth .
By . Associated Press Reporter . PUBLISHED: . 16:41 EST, 24 March 2012 . | . UPDATED: . 16:47 EST, 24 March 2012 . Robert Bales faces the death penalty after being charged with 17 counts of premeditated murder . U.S. investigators believe the U.S. soldier accused of killing 17 Afghan civilians split the slaughter into two episodes, returning to his base after the first attack and later slipping away to kill again. This scenario seems to support the U.S. government's assertion - contested by some Afghans - that the killings were done by one person, since they would have been perpetrated over a longer period of time than assumed when Army Staff Sgt. Robert Bales was detained March 11 outside his base in southern Afghanistan. But it also raises new questions about how Bales, who was formally charged Friday with 17 counts of premeditated murder and other crimes, could have carried out the nighttime attacks without drawing attention from any Americans on the Kandahar province base. The two American officials who disclosed the investigators' finding spoke on condition of anonymity because the politically sensitive probe is ongoing. Many details about the killings, including a possible motive, have not been made public. The documents released by the U.S. military Friday in connection with the murder charges do not include a timeline or a narrative of what is alleged to have happened. Bales, 38, is accused of killing nine Afghan children and eight adults. The bodies were found in Balandi and Alkozai villages - one north and one south of the base, in Kandahar's Panjwai district. Bales, a married father of two, was on his fourth tour of duty in Iraq and had been injured his lawyers say. The charge of premeditated murder means prosecutors believe the massacre was pre planned . Bales also was charged with six counts of attempted murder and six counts of assault in the same case. U.S. investigators now believe that . Bales walked off his base that night and killed several people in one of . the villages, then went back to the base. The American officials, who . are privy to some details of the investigation, said they do not know . why Bales returned, how long he stayed or what he did while there. Tears of grief: An Afghan youth mourns for his relatives, who were allegedly killed by the U.S. service member . Horrific: The bodies of an elderly Afghan man and a child killed in the Alkozai village of Panjwayi district are shown wrapped in blankets . He then slipped off the base a second . time and killed civilians in the second village before again heading . back toward the base. It was while he was returning the second time that . a U.S. military search party spotted him. He is reported to have . surrendered without a struggle. Bales is being held in a military prison at Fort Leavenworth, Kan. There have been previous suggestions . that Bales could have returned to base after the first set of shootings, . but the American officials who spoke to The Associated Press on . Saturday provided the first official disclosure that U.S. investigators . have come to this conclusion. Empty: The couple's Bonney Lake, Washington home was put on the market . for $229,000. Bales' wife and two children have been moved to Joint Base . Lewis McChord in Tacoma . Members of the Afghan delegation . investigating the killings said one Afghan guard working from midnight . to 2 a.m. on March 11 saw a U.S. soldier return to the base around 1:30 . a.m. Another Afghan soldier who replaced the first and worked until 4 . a.m. said he saw a U.S. soldier leave the base at 2:30 a.m. It's unknown . whether the two Afghan guards saw the same U.S. soldier. U.S. officials have said Bales left . the base the first time armed with his 9mm pistol and M-4 rifle, which . was outfitted with a grenade launcher. Bales' civilian attorney, John Henry . Browne, said Friday that he believes the government will have a hard . time proving its case and that his client's mental state will become an . important issue. Browne has said Bales suffered from the stress of . serving four combat tours. The decision to charge Bales with . premeditated murder suggests that prosecutors believe they have . sufficient evidence that he consciously conceived the killings. The maximum punishment for a . premeditated murder conviction is death. The mandatory minimum sentence . is life imprisonment with the chance of parole.
the U.S. soldier accused of killing 17 Afghan returning to his base after the first attack and murder and other crimes, could have carried out the nighttime attacks without drawing attention is accused of killing nine Afghan children and without a struggle. Bales is being held in a