By Published: March 1, 2016

man looking through a magnifying glass

For decades Jane Bock and David Norris have been using plant science to help solve murders.

Her name is Jill Coit, and she has been married 11 times to nine different husbands, two of whom were mysteriously slain. Coit has used more than a dozen aliases, but she’s best known as simply “The Black Widow.” 

After her ninth husband, Gerald Boggs, was found dead in October 1993 in his Steamboat Springs, Colo., home  —  clubbed with a shovel, tased and shot three times in the chest  —  the wheels of justice began to turn. Coit, who had never been charged in the 1972 suspicious shooting death of her third husband, started getting a lot of questions from law enforcement.

So did CU-Boulder faculty members Jane Bock and David Norris, internationally known experts in forensic botany, who were asked to join the investigation. 

The two key questions for the professors: What was Boggs’ last meal, and what was his estimated time of death? 

“From a law enforcement point of view, the stomach contents of victims are very useful  —  they can determine the subject’s last meal and help to identify the time he or she died,” says Norris, now a professor emeritus of integrative physiology. “At death the pyloric valve in the stomach shuts down, and whatever is in there remains as long as the stomach is intact.” 

The breakfast ordered by Boggs the day before his body was discovered was no secret: He ate at the same restaurant every day, The Shack, and ordered the same thing — eggs, hash browns, toast and coffee. During their stomach content analysis, Norris and Bock found traces of hash browns. They estimated Boggs had eaten breakfast just a few hours before his death. Coit and her boyfriend, Michael Backus, had a credible alibi for the time Boggs would have eaten his last dinner, says Norris — but not for the time following his last breakfast.

“Documenting that breakfast was his last meal was enough information that authorities now were able to get a search warrant,” recalls Norris, an expert witness in the case.

plants on a table

Investigators found a stun gun in Coit’s car that produced marks on a dead pig identical to marks found on Boggs. The evidence continued to pile up. In 1995 Coit and Backus were convicted of first-
degree murder with no chance of parole.

Bock and Norris primarily investigate the presence and condition of plant material in gastrointestinal tracts of murder victims. The method works largely because plant cell walls are durable, have readily identifiable characteristics and can survive most digestive processes.

The pair has also used plant evidence to document the location and movements of suspects and victims.

  David Norris Jane Bock

In 1999, for example, the body of a 19-year-old woman was found on a golf course in the Grand Bahamas. Investigators found tiny bits of grass on the socks and shoes of one of two men seen leaving a bar with the victim the night before. Bock eventually identified the grass as almond Bahama, which grew only on one of the three golf courses on the island — the one where the victim was killed. Bock’s testimony helped put one of the suspects at the scene and led to convictions of both.

In 1987, the CU pair were among the founding members of NecroSearch International, Ltd., a nonprofit, volunteer organization involving criminal investigators and scientists dedicated to helping locate clandestine graves and key evidence in cases in which foul play is suspected. The organization has by now assisted in 300 cases in 43 states and 10 countries.

Bock and Norris were not always sleuths. Norris arrived at CU-Boulder as a faculty member in environmental, population and organismic biology in 1966. He is an expert in animal physiology, including endocrinology, the study of hormones, which are chemical messengers that hop between cells and are intimately tied to health and disease. 

Bock and husband Carl joined the department in 1969, she as a botanist specializing in plant anatomy and evolution, he as an animal ecologist. Soon Bock and Norris were co-teaching general biology and swapping mystery novels on the side.
Their unanticipated careers in forensic science began in 1982 with a call from Dr. Ben Galloway, a CU professor and assistant coroner in Denver, after a young woman was found dead in eastern Colorado. Galloway found Bock’s name in a CU-Boulder course catalog and asked if she would analyze the victim’s stomach contents. 

Bock reluctantly agreed, and Galloway gave her slide sets with samples of the victim’s stomach contents. Bock then bought some typical salad vegetables. She and Norris chewed them up and made their own slide set for comparison. There were clear matches between the two, and no trace of hamburger in the victim’s samples — an indication that her last meal was not the fast-food hamburger eaten at lunch with her boyfriend, but rather a later meal eaten someplace offering green peppers, red cabbage and kidney beans.

The new evidence about the victim’s last meal helped support the alibi of the boyfriend, who claimed to be elsewhere later in the day when the woman was killed, says Norris. In the end, a serial killer confessed to the woman’s murder and confirmed the two had shared what was to be her final dinner at a restaurant with a salad bar.

As members of the American Academy of Forensic Sciences, Bock and Norris have worked on more than 50 criminal cases in the United States and abroad. They have lectured at colleges and scientific meetings in the U.S., England, Australia and New Zealand and given short courses for high school teachers and law enforcement agencies, including the FBI. Each has served as an expert witness on homicide cases, sometimes for the prosecution, sometimes for the defense. 

In January, Bock and Norris published Forensic Plant Science, a book intended for law enforcement officials around the world. It covers plant ecology and anatomy, evidence collection techniques at crime scenes and analyses of digested plant material. The book’s companion website will host an updatable microscopic atlas of common food plants.

Bock and Norris practically became rock stars in the world of true crime after several of their investigations were featured on the TV series Forensic Files, which was broadcast under several names from 1996 to 2011. Reruns of the show still air today.

“These documentaries are useful in spreading the word about effective, accurate forensic techniques,” says Bock, who, with Norris, continues to investigate crimes. “But popular crime shows in which detectives solve murders in 45 minutes are nonsense. There is nothing fast about our investigations, especially when it’s a matter of life or death.”

Photos by Glenn Asakawa; Headshots by Casey A. Cass