The Rosemary Nelson Inquiry team has begun work on its final report into allegations of security force collusion in the murder of the Lurgan solicitor.
Mrs Nelson, 40, died after a booby-trap bomb planted by loyalists exploded under her car in 1999.
The inquiry has heard 130 days of conflicting testimonies.
A panel of three judges will now review written submissions, transcripts of oral statements and hundreds of pages of unpublished intelligence material.
Summing up over the last three days, the inquiry's lead counsel, Rory Phillips QC, told the panel their work had only just begun.
He said they should be "bold in drafting their conclusions" and use the "margin of interpretation allowed".
Mr Phillips and the panel thanked the Nelson family for their cooperation over the last four years.
In 2004, Canadian judge Peter Cory recommended a public inquiry be held into allegations of collusion in the murders of Mrs Nelson, fellow solicitor Pat Finucane, Catholic father-of-two Robert Hamill and LVF leader Billy Wright.
The Wright, Hamill and Nelson inquiries subsequently under way.
However, the Finucane family rejected the government's offer of a public inquiry under the Inquiries Act.