A bright, witty, mischievous little man, the Robin Hood of the age, a Celtic chieftain-like figure full of guile and cunning, cocking a snook at authority? Or a murderous, sadistic little control freak with a miserable streak, a twisted sense of humour and irrational view of justice, who never did a decent day's work in his life?

The answer depends on who is doing the talking, their sense of humour and notion of justice. Martin Cahill's mind games for instance, were considered by some to be a great source of hilarity.

One of the legal devices he used to the maximum was the taking of depositions. This obliges prosecution witnesses to turn up in the District Court before the trial to read out their statements, a tedious process but useful for a defendant attempting to get their measure.

Dr James Donovan, head of the State's Forensic Science Laboratory, was finding it particularly tedious in December 1981. While Cahill was up on armed robbery charges and fighting strong forensic evidence, one of his little diversions was to have the scientist summoned time after time to give depositions, only to announce when he got there that he wasn't needed.

As a legal strategy to further Cahill's case, it served no purpose. As a form of harassment, humiliation and diversion of a valuable State resource, it worked just fine.

"This particular day," recalls Dr Donovan, "I went there again for the same purpose. As I was starting up the stairs, Cahill was coming down, and when he saw me he nearly did himself damage laughing. And when I went up, his solicitor said once again: `We don't want you'. So I assumed, of course, that Cahill was just laughing at the fact that he'd made a fool of me once again."

In fact, the laughter probably had a more sinister meaning. The following morning, as Dr Donovan drove to work, a device planted in his car blew it off the road.

"I was lucky because the car just happened to go off to the left-hand side into the grass and stopped safely." A few weeks later on January 6th, 1982, he wasn't so fortunate.

"I was just turning around at Newlands Cross and I suddenly saw a mushroom cloud in front of my eyes, and at the centre a great tongue of flame. Then I went blind. My eyes had been scored by the pieces of metal. And then I heard the explosion. I tried to move my right hand and I couldn't. It was paralysed. I put my left hand down and just past the knee, found bits of bone and a lot of squelchy material. . . tissue."

Both legs were threatened with amputation, the ulnar median nerve in his right hand had been severed and his sight was seriously impaired. Surgeons saved his legs and managed to reconnect the nerve. They rebuilt his foot by sticking three steel needles into his ankle, passing them through bone and "patting flesh around that".

Regular operations were required to remove decaying flesh that hadn't established a blood supply. There was the crippling pain of skin grafts from his back and thigh; "a pain worse than the injury itself which was messy looking enough to make me sick when I looked at it". To this day, it "bleeds and oozes, sometimes for weeks, sometimes for months".

He cannot walk without sticks or crutches. Worse, the left leg is now ice-cold and he faces a possible amputation. The pain has never abated. He has regular injections into his spine to clear a path for blood to the legs. Expensive medication is required to counteract the stomach and oesophagus damage caused by heavy painkillers. His eyes are still scarred with tissue.

"It's now a matter of waiting for it to grow fully across the pupils and I'll need a cataract operation."

His life has changed utterly. Although he is still head of the forensic laboratory, his injuries forced him into pure administration. His wife refuses to answer the phone or open the door.

"Sometimes, by the time you get through the front door and the locks and bars and things like that, you feel it might be quicker to sleep in the front garden. . ."

He has to wear several pairs of socks to absorb the blood and pus oozing from his legs, and virtually every time he sits down to remove them gingerly, he thinks about Martin Cahill. And he just can't see the fun of it at all.

"I had been involved with him for a very long time, trying to find evidence to show that he did certain crimes and also knowing the gardai who had been involved with him, and it would be difficult to find a story of his alleged humour or humanity. What would not be difficult though, would be to find a legion of stories of his inhumanity. . . He showed no mercy to anyone he had power over."

These included another State employee, the Social Welfare officer, Brendan Purcell, kidnapped from his home in front of his wife and young children, driven to the south city, dragged from his car and shot in both thighs. He had signed a form cutting off Cahill's dole, just doing his job.

The trauma to Mr Purcell's family and painful tissue damage to his thigh muscle are reminders of just how humourless Martin Cahill could be. There was the Cahill gang member who overdosed on heroin while they were on a house-breaking spree in Wexford.

"I don't know if he was dead or not. With an overdose you can go into a coma first", says Dr Donovan. "But Cahill drove into a Carlow village, dragged out this fellow and threw him on the ground, pulled his boots off so I wouldn't find traces for evidence and left him there, presumably not knowing if he was alive or dead. Even the Provos, if one of their own is injured, will take them to the door of the hospital, dump them and go away. But Cahill wouldn't do that because that would be a risk. People might identify him.

"And there was the case of an accomplice of his who raped his own 12-year-old daughter. Her mother's people protected her and tried to accompany her everywhere, but Cahill waited until he got her on her own and both attempted to bribe her with money and very severely threatened her. Gardai had to take precautions because it was felt that he could well kill her."

Denied the easy solution, Cahill then shot his accomplice in the leg to force a delay in the trial. Before that, he had one of his henchmen kneecap a young hot-dog vendor in Leeson Street who had defied an order to stop selling.

But these are the attention-grabbing headlines. The life-sapping, long-term trauma for the many victims of intimidation and house-breakings and others like the elderly widows preyed upon in their small shops are often overlooked. As are the consequences of "glamorous" raids for which the "master criminal" is much admired.

One Wednesday at 10 a.m., 140 people were employed in a Harold's Cross jewellery factory. An hour later, after raw materials built up over a generation had been stolen at gunpoint, the business was dead. Some of those present that day have never fully recovered.

Many people like these are at a loss to know how a man responsible for such suffering and devastation could be deemed a fit subject for a movie - any movie, rose-tinted or otherwise - while his victims remain mentally and physically raw.

Gardai refuse to accept that there was anything "great" or "ingenious" about his activities. "He was a shrewd robber and a good man-manager", said one. "He knew how to use and abuse the law and when the law didn't work for him, he turned to his usual means, like the larceny of files from the DPP's office and worse. You can call that cocking a snook at authority. I call it attempting to intimidate the State, and that means you and me and every law-abiding person in it."

"They were the first group that actively tried to intimidate me by following me out of court, snapping cameras," says Dr Donovan, whose dealings with the family began back in 1975. "At home, there were a lot of threatening obscene calls and silent calls and one night, when I was being followed by a large car, I thought I was going to die.

"Nobody is denying that Cahill committed crime, and yet there is a feeling that there's an attempt to excuse it, as if it were fun. People say there are humorous parts in the film, but my experience of his humour was his laughter that day as he came down the steps of the court and the following morning the bomb went off in my car. I find that a difficult humour."

Right up to his death, the Donovans never felt free of Martin Cahill. Not long before he was shot, they were told by a neighbour that a "short, stocky, plump fellow with black hair" had been on the garden wall watching their house. And when they heard he was dead? "Well, there was a certain satisfaction that you were no longer going to be troubled by somebody who had already caused you so much hassle and discomfort. Yes, it was a great relief."