Vital clues involving flies are helping detectives to solve crimes in which bodies are dumped in suitcases.
The impact that flies have on the bodies is the subject of groundbreaking research by the Metropolitan Police and the Natural History Museum.
Flies can potentially help officers to work out a more accurate time of death.
Police have tackled a number of investigations in which bodies have been found in suitcases, such as those of Alexandra Kovacs and Leah Questin.
Ms Kovacs' remains were found in a trolley case in Hendon, north London, last month, while Ms Questin, a care assistant, was killed in 2009.
Dr Martin Hall, an expert on entomology, the study of insects, worked on Ms Questin's murder case, which prompted him to direct the new study.
Ms Questin, 37, was found in a suitcase in a dried-up pond in the Kent countryside, after her body was dumped there by Clinton Bailey.
The study of how insects had affected her body was vital in establishing when she had been moved to the site, which in turn helped to prove that Bailey was the killer.
He was found guilty after a trial at the Old Bailey and jailed for a minimum of 30 years.
Dr Hall said: "The question there is, if there are blow flies on the body inside, did they occur before the suitcase lid was shut and zipped up, or can the blow flies penetrate through the zip?
"At the moment that question is unanswered so that is what we are trying to solve here."
Dr Hall, based at the Natural History Museum, said the scientific study of insects would become increasingly important in solving murders.
The latest research has been carried out by Poulomi Bhadra, a student from King's College, as part of her masters degree.
She has studied the behaviour of flies around different types of zips as they try to feed on animal meat or blood.
She said in order to determine the time of death, a forensic entomologist looked at three factors: the temperature of the environment; the species of fly; and the assumption that the fly had had access to the body immediately after death.
"But obviously if the body is disposed in a suitcase the access is the questionable part, and that is the question that I am investigating," said Ms Bhadra.
"It depends a lot on where the body is dumped, in what state it is dumped - whether it's whole or mutilated, and the type of zip on the case."
She added: "Sometimes you need the timeline to figure out the rest of your evidence.
"Sometimes you can't wait for separate research to be done on it so that you can give a more concrete answer.
"I hope that my work being done now will help future cases and future scientists working on this to more accurately give a time of death."