A judge is to decide whether a fresh inquest should take place into the death of a young soldier at Deepcut barracks 21 years ago.
Private Sean Benton, from Hastings, East Sussex, was found with five bullet wounds to his chest in June 1995 while undergoing training at the Surrey base.
His twin Tony and sister Tracy Lewis are going to London's High Court after they were given permission by the Attorney General to apply for a new hearing.
The move was made possible by their mother Linda who, before her death last year, used the Human Rights Act to access evidence held by Surrey Police.
The original inquest, which the 20-year-old's family say took less than two hours and heard evidence from six people, recorded a verdict of suicide, and a criminal investigation seven years later found no evidence of third party involvement.
Pte Benton's medical and mental health records were not obtained and no evidence was sought or given about his experiences at Deepcut.
The family, who are represented by human rights charity Liberty, believe he was subjected to severe bullying.
Pte Benton was the first of four young soldiers to die at the barracks between 1995 and 2002.
Private Cheryl James, 18, from Llangollen, North Wales, shot herself in November 1995, according to a second inquest into her death that concluded in June.
Private Geoff Gray, 17, from Hackney, east London, was found dead with two gunshot wounds to his head on September 17 2001, and Private James Collinson, 17, from Perth, was found dead with a single gunshot wound through his chin on March 23 2002.
Mrs Lewis has said: "More than two decades after our brother died - and having lost both our parents in recent years - Tony and I are determined to find out what happened to Sean."