He was a detective of the old school, an instinctive and skilful RUC man who was hell-bent on catching the most brutal killers in Northern Ireland and putting them behind bars.
And Jimmy Nesbitt, who tracked down most of the Shankill Butchers, even earned the grudging respect of some republicans who knew he didn't give a damn about the religious or political motivations for the hundreds of murders he had to investigate.
Yes, they criticised him and claimed he was part of a biased anti-Catholic old guard of a discredited force. But Nesbitt was widely regarded as an impeccably professional policeman who worked under extremely difficult circumstances to bring what he would call "the evil thugs" to justice.
To listen to his archived interviews in the wake of his death this week at the age of 79 has been to revisit the darkest days and nights of the Troubles when the under-resourced and under-pressure CID could scarcely keep a tally of the murders which were happening, never mind investigate them.
Yet even though the always well-groomed, silver-haired detective pulled no punches in describing the slaughter on the streets of north Belfast in the 1970s and 1980s, his uncannily accurate memories flowed from him with a quiet calmness as he talked of the barbarity of the Butchers or the depravity of the IRA who killed some of his closest friends and colleagues.
Nesbitt despised them all. And the senselessness of the tit-for-tat sectarianism in particular distressed and depressed him.
In an interview for Downtown Radio with presenter Bobbie Hanvey (right), Nesbitt talked movingly about one especially horrific weekend in November 1974 when nine people were killed in and around the Crumlin Road.
Nesbitt was able to remember all the murders. They started with a UDA shooting, followed by an IRA reprisal and then another loyalist revenge attack, which was the forerunner to yet another double murder by the Provisionals.
The last man who was murdered in that rampage was a Protestant killed by the UDA, who thought he was a Catholic.
"Not one of those victims was involved in anything at all. The whole thing was so senseless – just all with no reason at all."
Thirty years on, Nesbitt was able to remember with unerring clarity the fact that the victim had been returning home from buying a doll for his three-year- old daughter who had been ill. It was, said friends, an illustration of the very human side of a man who cared.
But while he may have been responsible for catching scores of killers, Jimmy Nesbitt's legacy will be his relentless hunt for the Shankill Butchers led by the manic Lenny Murphy who, the detective recalled, had poisoned a co-accused in prison.
Nesbitt got to know the psyche of the killers he hunted.
He had come face-to-face with dozens of the most ruthless murderers in police interview rooms. He said he looked for clues in the darkness of their eyes.
And he recalled how one of them told him he had been advised by a top UVF hit man from mid Ulster that one killing was never enough.
"He told him the best thing to do was to keep on committing murders and then you would forget what you'd done because they would all become jumbled up in your mind," he told Hanvey in 2001.
Nesbitt said the Shankill Butchers were "resolute and savage" killers who in their warped minds thought that murdering Catholics on darkened streets in Belfast was a way of hitting back at the IRA.
His contempt for the Butchers was clear. He talked of how they'd shot two Protestant workmen dead in a lorry, mistakenly believing they were Catholics.
"So perverse was their reasoning that the gang then planned to shoot six Catholics in retaliation for the two Protestants who had been killed," he said.
Jimmy Nesbitt said he and his detective team had gathered a huge amount of intelligence on the Butchers.
"It was like a big balloon waiting to burst and all we needed was a breakthrough just to put everything into place.
"And that came about with an attack on a young man by members of the Butchers gang.
"They slashed his wrists and they tortured him for some considerable time and left him for dead in an alleyway."
But the victim survived and told Nesbitt his story when he recovered. Then detectives drove him up and down the Shankill Road until he spotted two of his would-be killers.
"We knew a number of their associates and arrested them along with the two men who had been identified."
Under a floorboard in a bedroom the police found several of the butchers' knives used by the gang.
After the men were jailed at Belfast Crown Court, something unusual happened to Jimmy Nesbitt.
The next morning the mother of one of the gang telephoned him to thank him for what he had done.
He added: "In the case of another man, his wife called to see me and gave me a religious tract and told me she would pray for me and my colleagues for the work that we had done."
Nesbitt was known to journalists who covered the troubles in Belfast at the time as an approachable policeman who would share his insights and was convivial company after hours.
But when Bobbie Hanvey asked him in that Downtown Radio interview if he was a religious man, he replied: "I would say I have a quite good faith."
Nesbitt's one regret was that he was never able to convict Murphy of the Butchers' murders. Everyone who knew anything was too frightened to talk.
But Murphy was later shot dead by the IRA, who had been told where and when they could find him by rival loyalists.
Murphy's mother said her son wasn't a killer.
"He wouldn't have hurt a fly," she said.
Jimmy Nesbitt's thoughts about her comments will go with him to the grave.