BBC File On 4
Darren Wright looked destined for a successful military career, decorated for bravery in Afghanistan and an army boxing champion.
Instead he is serving an 11-year prison sentence for the violent kidnap, with five other men, of a wealthy businessman from Glasgow.
His family has no doubt the war hero became a criminal owing to a lack of effective care and treatment for post-traumatic stress disorder (PTSD) brought on by horrific scenes he witnessed in Afghanistan.
"He got this idea in his head he'd got to protect his family so he slept downstairs as if on guard waiting for the enemy to arrive," his stepmother Mary Costigan told BBC File On 4.
The Ministry of Defence on Tuesday reported diagnosing almost 4,000 new cases of mental illness among forces personnel last year, with those sent to Afghanistan or Iraq most likely to be traumatised.
Wright, a 33-year-old father-of-five, used to take gifts to Afghanistan for the local children when he was on peacekeeping duties but became extremely distressed at having to move and bury the bodies of little children caught in the crossfire of battle. He suffered nightmares, flashbacks and became delusional, once walking into a Manchester hospital hunting for Osama Bin Laden.
The serving soldier was handed back to the Army, where he was assessed by army psychiatrists and eventually forced to leave under an administrative discharge.
Consultant psychiatrist Dr Dafydd Alun Jones, who has spent 25 years preparing forensic reports on traumatised ex-servicemen, said Wright was suffering PTSD.
"He should have had a medical discharge with onward reports to the NHS for further help," he told File On 4.
Instead Wright's mental state deteriorated, he began to drink heavily, his marriage broke up and at a low ebb in September 2006 he fell in with a criminal gang and agreed to join the kidnap plot.
The three-week abduction saw 800 officers from six different forces tracking the kidnap gang.
Wright told the court he believed the kidnapped businessman was taking part in tax fraud to fund terrorism. In fact the man was entirely innocent.
Dr Jones explained: "His perception was very distorted."
According to psychologist Nikki Scheiner, even vets discharged with PTSD have difficulty accessing NHS services or finding GPs who understand their condition. They also suffer from a lack of resources and a lack of understanding from community mental health teams.
The psychologist, with the Traumatic Stress Service in St Georges Hospital, south London, has carried out detailed interviews with vets such as a former special forces man with acute symptoms who was referred to his community mental health team and promised a home visit.
"He told me almost three years later he got a phone call from someone saying, 'Sorry, mate, we're running an hour late, we'll be round later,'" she said.
Another veteran, who has twice tried to commit suicide, was referred by his GP to a specialist respite centre run by the charity Combat Stress.
But he says he "got no follow-up or backing whatsoever" after returning home. "I haven't even got a community psychiatric nurse."
Veterans minister Kevan Jones told File On 4 he wanted to hear from veterans who had difficulty accessing mental health services.
"As veterans minister I want to know, because it is those individual cases I want to champion and to say, not just to the Health Minster but to local strategic health authorities, 'Why has a case fallen through the system?'"
Mr Jones denied there was a widespread problem across the UK.
"I would not want you to go away with the impression that somehow the NHS everywhere in the country is failing veterans in some way on mental health.
"In some places veterans are getting very good care from mental health."
However, he added: "But you [File On 4] have clearly identified some problems, I want to know where they are and I want to be able to sort those problems."
He promised to take action on individual cases presented to him from File On 4 as part of its investigation.
Veterans groups say many traumatised vets are in jail instead of receiving much-needed therapy.
These claims are backed by the National Association of Probation Officers (Napo), which published research in August stating there were 12,000 ex-forces personnel in jail or on probation - nearly double the previous Home Office findings of 2004.
Harry Fletcher, Napo assistant general secretary, said told File On 4: "It is not surprising the vast majority involved either a soldier on leave or following discharge from the Army, finding it extremely difficult to adjust possibly with PTSD, getting involved in drugs or alcohol and then subsequently getting involved in fighting."
Ironically, once these vets are in prison they may finally get the treatment they need.
According to Mary Costigan, Darren Wright says getting jailed is the best thing that could have happened to him.
"This is simply because he has been assessed by psychiatrists, he's getting some medication and it is helping him," she said.
She added: "I think it is very sad that you've got to commit an offence as serious as Darren did and end up in jail, after being a decorated soldier and a very brave person, to get some treatment."
6 months ago