Ms Collins said on her way to caucus today a report could take up to two months.
The call for disclosure of a person's criminal background came after Jeremy McLaughlin was convicted for his second killing of Christchurch schoolgirl Jade Bayliss.
He was deported to New Zealand after serving a manslaughter conviction in Australia - but was not subject to any release conditions.
Only when the guilty verdict in the Bayliss case was handed down could it be revealed that he had killed before.
On his arrival in New Zealand, police were advised of the manslaughter conviction, but McLaughlin was not subject to any release conditions or monitoring because the crime occurred in another jurisdiction.
Christchurch police confirmed they knew of McLaughlin's past, but were unable to tell anybody about it - even Jade's mother, Tina who became worried about McLaughlin's behaviour after ending a four-week relationship with him just weeks before he killed her eldest child.
Unaware of his previous convictions, she sought a trespass order against him.