The mother of murdered student Sally Geeson has blamed the British Army for her daughter's death.
Miss Geeson went missing after a New Year's Eve party
It has emerged that police could not access information about Lance Corporal Atkinson including a 1998 conviction for falsely imprisoning a young woman.
The Ministry of Defence says it passed on Atkinson's record to the police.
But File on 4 has learned that when other women came forward to make allegations about him, the information did not show on police record checks.
Asked who she held responsible for her daughter's death, Sally's mother Sue Geeson told the programme: "I think the army are. I think they've got a lot to answer for.
"The army knew his record, they knew what he'd done and what he was probably capable of. The police had nothing on their national database with regards to Atkinson and his convictions or the fact that he was even in the area.
"So the police wouldn't have had any cause to know him or look for him or anything until the military got in touch. The public wasn't protected, and it resulted in us losing Sally.
Mrs Geeson also told the programme the army waited four days before reporting the disappearance of Atkinson at New Year - during which time repeated appeals were made in the media about the missing 22-year-old.
In the early hours of New Year's Day, Atkinson, 31, set fire to his room in Waterbeach Barracks, Cambridgeshire, and fled. The fire was discovered at 0300 GMT on New Year's Day, shortly after Sally disappeared, but although his superiors knew of his history they did not report the incident to the police until 5 January.
File On 4 reveals that on two separate occasions after 1998 the army was informed of serious allegations about Atkinson by young women. On one occasion the complainant was told that the soldier's actions were not a matter for the army.
In the summer of 2001, Atkinson was posted to Claro barracks in Ripon, North Yorkshire. In a nearby pub he chatted to a local 16-year-old girl - who does not want to be named.
He then took her to an isolated spot where he pinned her to a bench and subjected her to a violent sexual assault during which she feared she would be killed.
The girl's mother told File On 4 that shortly after the attack she was called to collect her daughter - and found her in a distraught state.
"Her clothes were all in disarray, she was hyperventilating, she was hysterical, she had red marks on her neck where he'd held her down on a bench and nearly strangled her.
"She was just crying and saying, 'I thought he was going to kill me, Mum,'" she said.
Atkinson's semen was found on the girl's clothing, but he claimed she had consented to the encounter. Police told the family that no charges were to be brought.
Her mother says she told the police: "Does David Atkinson have to kill somebody before anyone can do anything about it?"
Atkinson jumped to his death at a Glasgow hotel days after the murder
The local army base also told her there was nothing they could do.
"They said that it was in the hands of the civilian police, therefore it wasn't a military matter. Because he hadn't been prosecuted, so far as they were concerned he was innocent.
"I felt that knowing they were harbouring somebody like him, they should have done something to ensure that wherever he was, he wasn't going to be a threat to the local girls."
In 2003, when Atkinson was stationed in Chatham, Kent, another young woman came forward to make an allegation of sexual assault against him.
Again, the complainant also informed the army of what had happened.
As a result of Sally Geeson's death, Michael Bichard, who is conducting an inquiry into the aftermath of the Soham murders, has been asked to extend his investigation into how the army informs police about soldiers' criminal records.
The Ministry of Defence said it had passed on Atkinson's record to the police. But several police forces confirmed to the programme that they were unable to find it.
File On 4 also learned from the detective in charge of the Sally Geeson inquiry that the first entry on the police computer about Atkinson was made by his team in January this year.
Brigadier Stephen Andrews, the army's director of personal services, said: "We feel there are areas where we are going to have to work very closely with the civilian police to make sure those links are as strong as possible."
File On 4: BBC Radio 4, Tuesday 1 March, 2005 at 2000 GMT, and repeated on Sunday 6 March, 2005 at 1700 GMT.