When time is of the essence...

As anyone who has watched a murder mystery programme will know, there is one question the investigating officer always asks. Whether it is DCI Barnaby on the hunt for the latest serial killer in Midsomer or Miss Marple trying to uncover the evil deeds of one of her St Mary Mead neighbours, they are always keen to know what time the victim met their grisly end. And it is not hard to see why.

By pinpointing the time of death, investigating officers are able to identify potential suspects and also exonerate people who could not have been at the scene of the crime.

It is also a key part of the jigsaw in tracing the dead person’s final movements.

Common ways of estimating the time of death include the change in body temperature, the degree of rigor mortis and even the extent to which the last known meal has been digested. But a University of Wolverhampton forensic scientist has been investigating a different way of pinpointing the time of death.

Crucial cartilage

Christopher Rogers is researching how cartilage could be used to identify the time that has elapsed since a person has died.

As cartilage does not have a blood supply and therefore breaks down more slowly than other tissues, it could prove a useful tool to police and pathologists in suspicious cases. To conduct his research, PhD student Christopher, from the School of Applied Sciences, has used pig trotters. By burying the trotters in soil he was able to replicate the effect of human burials in shallow graves.

The trotters were left for varying amounts of time and then tested. Christopher found that crystals formed on the cartilage after three weeks and started to disappear after six, enabling him to identify the time of death.

Significantly, this result was consistent over the three years of the study and in hundreds of examples. The tests included looking at the trotters macroscopically to see if there were any visible changes, such as colour.

They also analysed the trotters using a scanning electron microscope, which identified the formation of crystals.

The importance of environment

One aspect that can affect the accuracy of determining the time of death is the environment at the scene.

For example, if left outside a body will be subject to the elements, such as potentially dramatic changes in temperature and the impact of wildlife.

Again this is where cartilage could prove a useful indicator, as it is protected.

Christopher, who also studied a BSc (Hons) in Forensic Science at the University and is due to complete his PhD this year, says: “The findings could be useful in determining how long a person has been dead for, which is an important question in a suspicious death investigation. It could also help to identify a suspect or exonerate someone.

“There has been little research into cartilage degradation post-mortem, but it is useful as it is contained within a trotter so is protected from the effects of the environment. This would be the case for a human body too, as cartilage is protected by muscle and skin.”

As well as being useful in suspicious death cases, the process could also be used for wildlife forensics, for example investigating allegations of poaching. If an animal carcass is discovered outside of legitimate circumstances, the analysis could be used to identify the time of death.

Forensic science as a career

The career of a forensic scientist is interesting, challenging and intriguing and the courses at the University of Wolverhampton provide an excellent grounding for this profession.

As well as state-of-the-art science labs, students are given a taste of what could face them in their daily working life in a scenes of crime suite at City Campus. The fully furnished flat was designed with help from West Midlands Police, and features CCTV cameras, dummies and replica weapons.

Lecturers use the suite to simulate murders, assaults and break-ins and other scenarios. It includes a central teaching lab where students can examine fingerprints and analyse samples found at the scene.

And although the detectives on the popular television programmes may seem to rely on hunches and hearsay from local residents, they would no doubt find the facilities and research at the University of Wolverhampton useful in reaching a conclusion in their most baffling cases.