Video: Unlocking clues to Kent's major unsolved crimes

The team is based in Chatham and is made up of DCI Withers, three detective constables and two retired detectives acting as investigating officers.

Recent successes include the jailing of Kelvin Bennett and the discovery of the murderer of Evelyn Staples.

The team is also reviewing the murders of Caroline Pierce and Wendy Knell, from Tunbridge Wells. DNA has been recovered, which detectives believe is from the offender.

Samples have been taken from people connected to the case – with their permission – and so far officers have eliminated more than 500 people.

DCI Withers said: "We don't contact a victim or a victim's family until we have identified an offender. We wouldn’t want to raise their hopes unnecessarily or to resurrect old memories for no reason.

"With the Wendy Knell case her parents want to do anything they can to help catch their daughter's killer. They cannot rest until the killer is found."

Work with cold cases starts at police headquarters in Maidstone with the Serious Case Review Team, which reviews unsolved murders and rapes to find more leads. If a murder remains undetected for 28 days it joins the cold case unit.

Head of the Serious Case Review Team Dave Stevens, a former detective superintendent, said: "We can now get DNA from things we couldn't 10 years ago. We compare DNA samples against a national DNA database and we also have a data base of DNA taken from (crime) scenes, so we can link one offender to more than one crime.

"We also know that family members have similar DNA, so if there is a close match we can then investigate relatives."

If you have information which might be helpful contact Cold Case Investigation Team on 01634 884048.