During 30 years with Sussex Police, Det Supt Tim O'Connor has tackled some very high-profile cases.

He will be best remembered as the man who helped put notorious child attacker Russell Bishop behind bars. He led the investigation into the attempted murder of a seven-year-old girl from the Whitehawk estate in Brighton at Devil's Dyke in 1990.

Bishop, 33, a roofer from Brighton, is serving life after being found guilty of the charge and of kidnapping and indecently assaulting the girl. Four years earlier, Bishop had been found not guilty of murdering nine-year-old playmates Karen Hadaway and Nicola Fellows at the Wild Park in Moulsecoomb.

Mr O'Connor testified to the Devil's Dyke jury that some police felt Bishop had been wrongly acquitted of the Wild Park murders, but that had no bearing on the prosecution of the Devil's Dyke case - he had never even read the Wild Park case file.

The Devil's Dyke case earned him one of his seven commendations from the force, but to this day he insists it was a team effort. He said: "It was not an especially-difficult case to investigate. There was an enormous amount of evidence which we found."

Mr O'Connor led investigations into a number of high-profile murders, including that of housewife Marion Rilka, found with her throat cut at her home in Hove in 1991. Her only mistake was being at home when killer Gary Gregory called on a mission to steal. She picked up the telephone and managed to dial just 99 when he leapt at her with a knife.

Relaxing at his Sussex home, Mr O'Connor looked back fondly on his career and his rise from humble beginnings as a labourer in his native Ireland. Born in Cahir, Tipperary, he left school at 13 with no qualifications - his biggest regret in life.

He went to Manchester as a welder but after his fourth visit to hospital to have metal splinters removed from his eyes he decided to pursue an idea born back in Ireland - to serve as a policeman. He hoped to start his career in Liverpool because of its proximity to his homeland, but the positive reply to his applications came from Sussex.

Mr O'Connor's story-telling has earned him a reputation as a blunt, humorous orator and he is a popular choice for speaking at leaving events and dinners. He once welcomed this reporter at a CID dinner with the words: "He comes to the police station every day and we sit down and sort out good stories from the crap, and he goes back to the Argus and prints the crap."

Mr O'Connor's varied career has supplied him with a wealth of material for his speeches.

He rose from PC to Sergeant in five years, served in Crawley, and then Horsham, with the surveillance unit. He was promoted to Inspector in 1983 and a year later became Det Insp at Brighton. He was appointed Det Chief Insp and head of Brighton CID in 1988 and stayed for three years.

After stints in West Sussex, the Regional Crime Squad and in Hove-Shoreham, he took up his final post as Det Supt and Counter-Terrorism Liaison Officer with the Home Office, acting as a link between the Association of Chief Police Officers, Foreign Office, special forces and security services.

It was a job that took him on security missions around the world and to countless meetings. Mr O'Connor is thought to be the only serving British policeman with an Irish passport to receive the Queen's Police Medal, an honour bestowed by the Queen this year for his distinguished service.

His counter-terrorist work included the close protection of Sinn Fein President Gerry Adams. He avoids talking Irish politics but is hopeful permanent peace has now arrived and firmly believes Britain's anti-terrorism system is the envy of countries around the world, as is our judicial system.

British police are also respected worldwide but his foreign counterparts can't understand why people in Britain take any notice of police officers who are unarmed. He said: "They don't understand that we are unarmed because the great British public allows us to be unarmed. We really have to cherish that concept."

One issue in Sussex particularly angers him - five officers charged over the police shooting of an unarmed wanted man in Hastings more than two years ago. They have been suspended and still await trial, a delay he describes as being against natural justice. "Other accused people have been tried, acquitted or convicted, jailed and released in that space of time."

Mr O'Connor, 57, once drew a sketch of J.F. Kennedy which found its way to the White House via a travelling salesman and was sent back to him, signed by the late President. It arrived only weeks before Kennedy was assassinated.

He has had his share of disappointments, but no regrets. "During a trip to Bogota, Colombia, I remember sitting in a hotel lobby and feeling a bit lonely and sorry for myself. Then, looking out the window to the street, I saw a man in a wheelchair lurching from side to side. I soon realised why.

"He had no legs and only one arm. He had to keep switching his one hand from one wheel to the other to propel himself. I made a promise to myself then. If I ever get down, remember Bogota."