BBC Scotland News, Highlands and Islands reporter
A former soldier who committed suicide in prison took up extreme climbing to show the army it was wrong to let him go, his brother said.
Former Royal Green Jacket Alan Mullin in action on a climb
Alan Mullin, 34, went on to become highly regarded by some of Scotland's top mountaineers.
A fatal accident inquiry into his death in Porterfield Prison, Inverness, has been adjourned until 7 January, 2008.
Kevin Mullin said his older brother was spurred on by a medical discharge from the army after an accident on duty.
In an interview with BBC Scotland, Kevin Mullin described his brother's increasingly intense fascination and determination to tackle Scotland's toughest climbing routes.
The 31-year-old warrant officer at the Small Arms School Corps, who formerly served in the Royal Green Jackets the same regiment as Alan Mullin, said: "He decided to join the army from a very young age.
"He went with the army to South Georgia, which is just off the Falkland Islands.
"While they were there they did ice climbing and under supervision they were lowered into an ice crevasse, given two ice axes and a set of crampons to see who could climb out the quickest."
Alan Mullin slipped and badly damaged his back. Following operations on his injuries, he was medically discharged.
Kevin Mullin said: "He did ask them not to because he said he could prove to them that he was fit enough to do the job, but at the time they weren't hearing any of it.
"He decided to prove a point to the army and to prove a point to himself as well, so he took up extreme mountain climbing."
After his discharge Alan and his family moved to the Inverness area, which put many of Scotland's most challenging peaks within easy reach.
Bi-polar disorder had not been diagnosed at that stage, said Kevin Mullin, but the signs may have been there as he threw himself into climbing.
"With bi-polar disorder when you focus on something you become infatuated to a degree with it and I think that had to do with a bit of his training," said the warrant officer.
Meanwhile, his determination to prove a point to the military also lay behind his rigorous training regime.
Kevin Mullin said: "He was adamant that he would do something to such a degree that people would turn around with amazement and say 'my God, I can't believe we let him go and look what he is doing now'."
Sepyside-based climber Andy Nisbet recruited Alan Mullin to make the first winter ascent of Threadbare, a route on the Shelter Stone Crag.
'Fire of ambition'
Mr Nisbet said: "He was extremely strong and determined, but yet quite cautious.
"He was sort of nervous but was very determined to succeed. Success was very important and the two were in conflict."
Recalling the successful attempt on Threadbare, he said: "I had been interested in this climb for a while, but it was really a bit too hard for me and I needed someone stronger to help me up it.
"Alan was very strong. He trained very hard throughout the summer in order to make a winter ascent.
"It was quite a nice day with deep snow so it was a hard walk in. To do this climb you need a lot of snow to be in winter condition.
"For me that was the most memorable climb with Alan."
Friends said Alan Mullin was safe and competent climber
Climber, writer and photographer Andy Kirkpatrick said the former soldier's style and background made him a misfit in the climbing community.
He said: "The thing about climbing these days is that it is a predominantly middle-class sport really done by professionals or would-be professionals like students.
"Alan, who was really as working class as you could find, really stood out.
"I think he didn't speak the same language as everybody else and was socially dysfunctional in that situation, but you could tell he was ambitious and the fire of ambition was really burning inside him."
For Kevin Mullin, the interest in adventure and wanting to do what others would not started when they were boys.
He said: "When we were young lads we lived on the top of a steep bank and across from that was a forestry block and a river.
"The young kids would play on rope swings, but no-one would climb up the trees to put up the rope in order for us to do that.
"But Alan was always volunteering and always climbing the trees."