The detective who headed the inquiry into the disappearance and murder of Soham's Jessica Chapman and Holly Wells is retiring after a 30 year career.
Det Ch Supt Stevenson, the Soham inquiry leader, is to retire
Det Ch Supt Chris Stevenson, 55, led the team which brought double murderer Ian Huntley to justice.
His work also secured a conviction against Maxine Carr for perverting the course of justice.
He took over the inquiry, ordered another search of the school and found the girl's Man Utd shirts.
The detective took a down to earth approach to the case of the girl's disappearance.
He said: "What we did was a back to basics approach. I believe you have to clear the ground under your feet.
Pointed towards Huntley
"I felt the inquiry had spread out too far and one of the things I did was to order a re-search of the school.
"We also had, at that point, some initial telecoms evidence relating to Jessica's phone which pointed us back in Huntley's direction."
His decision to refocus the enquiry led to new information about Huntley's alibi, the school caretaker rapidly became the prime suspect.
Through painstaking and thorough work by the team, Huntley was forced to change his story to the point where he had to accept that he was responsible for the deaths of the two girls - although he continued to deny their murder.
The Old Bailey jury decided the evidence was compelling and found him guilty.
Mr Stevenson said: "Some murderers have taken 20 years to fully admit their guilt. But I hope at some time he will see his way to telling us exactly what happened.
"Whatever possessed him to do it only he knows."
He said: "I want to spend more time with my family. I have three grown up children and four grandchildren with two more on the way."
During his 30 year career Det Ch Supt Stevenson has worked predominantly in his home city of Peterborough.
He has also worked in March, Huntingdon and the Operational Support Services based at police headquarters at Huntingdon.
His early uniformed career included spells policing the miners strike and the peace camp at Molesworth in Cambridgeshire.