Margaret Pereira liked to tell a story about when she was a young forensic scientist, back in the late 1950s. A body was found in the driving seat of a car that had crashed into a tree. The deceased, a woman, was covered in blood and had extensive head injuries. Police at the scene deemed the cause of death to be “accidental”, but when Pereira arrived she suspected foul play.
The direction of the blood splashes on the exterior of the car suggested to her that the victim had been outside the vehicle at the time she was injured. Further investigation revealed a semi-circular bloodstain on both sides of a split in the car’s body work, indicating that the damage had occurred after the blood had fallen on to the car. There were also bloodstains on its lower surface, which revealed that the woman had at one stage been on the ground beside the car. A trial followed, and the woman’s husband was found guilty of murder.
The denizens of Fleet Street liked the story too and Pereira was duly dubbed “Miss Murder”, a play on the name of the popular Agatha Christie character Miss Marple. However, Pereira’s true claim to fame was yet to come. In 1962 she was hailed as the pioneer of a new technique that made it possible to match blood traces to different blood groups. “In the past it was necessary to have a blood stain at least the size of a sixpence on clothes or other articles before it could be accurately grouped,” Pereira said about her discovery. “Today the result can be obtained from a spot the size of a pinhead — just one minute speck of blood may help to trap a killer.”
The “Nicholls and Pereira” method, as it was called (Lewis Nicholls was the director of the Metropolitan police’s forensic science laboratory, where Pereira worked), became the standard procedure for blood grouping in the UK and was eventually used around the world. Alan Scaplehorn, who worked at the Home Office, said: “People are so used to DNA these days, but back then it was extremely difficult to pinpoint evidence. Margaret wanted to make blood grouping possible. It was the only weapon in the armoury of a forensic scientist then and she knew the technicalities of it needed to be developed.”
It was because of Pereira’s work on blood typing that her colleagues called her “Bloody Maggy”.
Advertisement
Margaret Pereira was born in Bexley, Kent, in 1928, and began her education at La Sainte Union convent in Bexleyheath, before attending Dartford County Grammar School for Girls. From a young age she was filled with curiosity and would enjoy taking her toys apart, “not because I’m destructive, but because I wanted to see what they were made of, what was inside”. She had ambitions to become a doctor, but when she finished school in 1946 she realised that places available to women medics were scarce, and were further limited because of the large percentage of university places allotted to war veterans. Unfazed, Pereira went to the local juvenile employment bureau and was told of two jobs going: trainee laboratory technician with the Metropolitan police at £3 8s a week or hospital work at £2 8s a week. “I made the obvious choice,” she said.
“She devised a technique in which a tiny speck of blood could trap a killer
In 1947 she became the first woman on the Metropolitan police’s laboratory team. Realising that she required a bachelor’s degree to progress at the lab, she attended evening classes at the Chelsea College of Science and Technology. “They never envisioned women being anything other than junior assistants, but there was a professor with a more enlightened attitude and he encouraged me,” she said. “I wanted to do the real job myself; I wanted to be in charge of scientific investigation.”
When she graduated with a BSc in 1953 she was able to stand as an expert witness in court, although not without further stigma. It was thought that, because she was a woman, she would break down in tears under heavy cross-examination. One judge sent a note after she had given evidence in court in which he said that he had never had such an “embarrassing experience” and requested that Pereira not be sent to his court again.
Her most high-profile investigation came in 1974-75, when she provided forensic evidence in the Lord Lucan case. It helped a jury to find the vanished earl guilty of murdering Sandra Rivett, the family’s nanny, and injuring his wife, Lady Lucan, at their home in Belgravia, London. Pereira had conducted tests on a lead pipe stained with blood that had been found in a car that the earl had borrowed and later abandoned. She discovered that blood found at the scene, and on the pipe and the car, matched the blood groups of Rivett and Lady Lucan. “I think as a gambler Lucan would have gambled on getting away,” she said after the case.
In another murder trial at the Old Bailey, Pereira investigated the death of Claire Josephs, a 20-year-old newly-wed who was found dead in her home by her husband in 1968. Pereira’s forensic findings linked saliva on a coffee cup, fibres from a scarf under the thumbnail of the victim and bloodstains in a car to Josephs’ killer, a bank clerk named Roger Payne, thus clearing her husband, who had originally been suspected of the murder. She later met Josephs’ husband by chance and when he thanked her she burst into tears. A press report noted that “it was the only time she let down her professional guard in public”.
Advertisement
Pereira’s career progressed quickly and she was made principal scientific officer in 1969 before gaining another promotion for “individual merit”. Six years later she left the Metropolitan police to become the deputy director of the Home Office’s central research laboratory in Aldermaston, Berkshire.
She rose to become the first female controller of the Home Office’s now defunct Forensic Science Service, where she reported directly to the home secretary. She was responsible for six regional laboratories, the research laboratory and a scientific staff of more than 600 people. She retired in 1988 with “very mixed feelings”. It enabled her to spend more time with her husband, Arthur Wells, a childhood friend and an engineer whom she married in 1980 and who survives her, but she regretted not being able to use the latest techniques.
“It was good to have more private life and be rid of the political stress,” she recalled in a speech to a forensic science conference in America in 1997. “But I would have liked to have been young again and personally involved in the exciting developments, particularly in the field of DNA technology.”
During her long career Pereira was under no illusions as to the limitations of serology (the diagnostic study of blood serum) and she always hoped that a more effective way of profiling would one day be developed. Anticipating how revolutionary DNA testing would prove to be in criminal cases, she pushed for all her staff working in laboratories to be trained in genetics.
While Pereira believed in equal pay and opportunity, she never considered herself a “a card-carrying feminist”. Despite her groundbreaking achievements, she retained a sense of modesty. “We are just receivers of goods that are analysed as part of the process to support police work,” she said of forensic scientists. “Evidence like this is never solely responsible for convicting somebody, but is part of an important process for not sending an innocent person to jail.”
Advertisement
Although she was slight of frame, it was said of Pereira that she had “the stamina of an ox” and a constitution to match when it came stomaching the most macabre of scenes. And, given the number of gruesome murder cases she worked on, it was perhaps no surprise that her sense of humour was described as “wicked”.
Margaret Pereira, CBE, was born on April 22, 1928. She died on December 22, 2016, aged 88