The Brighton bomber has appeared in a TV documentary marking the 40th anniversary of the devastating Grand hotel blast.
Patrick Magee told BBC Two's "Bombing Brighton: The Plot to Kill Thatcher" that “violence happens”.
Magee received eight life sentences for his role in planting the bomb which targeted Prime Minister Margaret Thatcher. She survived but five people were killed.
Magee was released in 1999 as part of the Good Friday agreement, having served 14 years of his 35-year sentence.
The BBC also spoke to Edward and Jo Berry, whose father MP Sir Anthony Berry was killed in the blast.
The documentary explored Jo Berry's relationship with Magee following his release from prison. She said she has met with him over "300 to 400 times at least" over the course of the last few years.
Asked if there was a conclusion she wanted to reach, Ms Berry said: “Is there a place to get to?
“If there is such a place, it would be him saying ‘nothing is worth killing someone for’.
“He says that he will never forgive himself. He isn’t saying what he did was wrong because he is holding on that they [the IRA] had no choice.”
The BBC asked Magee: "Do you think the learning from this would make it impossible to carry out something like the Brighton bomb ever again?"
He replied: "I think the very fact that you know more about a person makes it impossible."
He later added: "The work with Jo has been my response."
The documentary included an interview with Lesley Brett, who at the time was sales manager at the Pink Coconut nightclub in West Street.
Lesley heard the blast which ripped through The Grand at 2.54am on October 12, 1984. Mrs Thatcher and other senior Conservatives were staying at the hotel during the Tory Party conference.
“We were probably about 20 yards shy of the corner of West Street and had crossed at the traffic lights,” Lesley said.
“I’d never heard such a loud explosion in my life. The ground trembled like it would do during an earthquake, my immediate thoughts were that it was a gas explosion.
“The whole thing [The Grand] was enveloped in this huge cloud of dust. I could hear masonry falling, I could hear metal scraping and people screaming which was the most dreadful thing.
“It was such a shock.”
The documentary also includes interviews with John Gummer, former Conservative Party chairman, who was with Mrs Thatcher in the room the moment the bomb went off, and a Special Branch surveillance officer responsible for trying to prevent IRA attacks in England during the 1980s.
The Argus is publishing stories in print and online every day this week to mark the anniversary of the bombing.
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