Anton St Paul, Spencer Yiadom, Aaron O'Brien, Duane King, Michael Tucker and John Moody are just some of those serving long sentences as a result of murder inquiries led by Detective Chief Inspector Jes Fry.

He also headed the tragic double death inquiry on the Norfolk Broads earlier this month.

But after 28 years of working to try to make Norfolk a safer place, he has served his last day with the force.

He has spent the past five years with the joint Norfolk and Suffolk major investigation team (MIT), which deals with investigations into the most serious crimes including murder, manslaughter, rape, kidnappings and extortion.

He said: 'It's been full on. I've been involved in lots of different things but since coming here I've had the opportunity to lead them, which is a different proposition because then you've got the responsibility for the direction and decisions taken around very high-profile investigations.

'It's been up to me make the key decisions and direct these investigations. It's one of the greatest challenges because it comes under the greatest scrutiny at court. Everything has to be done to the highest level to stop any acquittals down to some sort of oversight. There's a level of intensity that you don't get with some other inquiries.'

Of all the 50 or so cases Mr Fry has led over the past five years, there are just two that remain unsolved: the murder of 17-year-old Alisa Dmitrijeva, whose remains were found on the Sandringham estate on New Year's Day, and the killing of Londoner James Davis, 25, who was stabbed at a house in Norwich in 2010 during a drugs gang raid.

Mr Fry said he regretted not being able to help identify those responsible committing these two crimes, but said he was satisfied to have been able to help solve so many others.

He said: 'There's a lot of satisfaction but you temper that with the fact there's always a victim and the families of that victim.'

As well as live inquiries, Mr Fry has also assumed a lead role in trying to solve a number of historic cases since the formation in 2008 of the cold case team to investigate murders, missing people and serious sexual offences that have been unresolved.

He said: 'You hope that you can make a difference, but they're very, very difficult to bring to a successful conclusion. I would have liked to have brought a resolution for the families. It's very frustrating not to have been able to do it so far but obviously that work will carry on.'

Originally from Kent, Mr Fry was an RAF policeman before joining Norfolk Constabulary in 1984. He was initially posted to Thetford, then went to Watton before joining the CID, working Thetford, Swaffham and Norwich, and was promoted to sergeant, working in Sheringham and Norwich. He later went back to CID in Norwich as a detective sergeant then a detective inspector before going to the MIT.

He said it will be strange to start a new life away from the police. 'I've been called out on the last two Christmas Days, New Year's Day, Mother's Day. It has had a significant impact on the family, who have been very supportive.'

Mr Fry, a father-of-four and a grandfather-of-one, said he had not yet decided what he wanted to do, but wanted a new challenge.

But he will never forget his time in the force. 'You can't just cut it off and leave it all behind. I will be interested to see how things progress.

'I've been very lucky to have a very varied career and I've had the privilege to work with some fantastic officers who really believe they are making a difference and helping the community.'