The Office of the Chief Medical Examiner in Baltimore, Maryland is a busy place. Anyone who dies unexpectedly in the state of Maryland will end up there for an autopsy. On an average day, they might perform twelve autopsies; on a more hectic day, they might do more than twenty.

But there’s one room on the fourth floor that sits apart from the buzz of normal activity. It feels a bit like an art gallery.

This room houses the “Nutshell Studies of Unexplained Death.”

The Nutshell studies are eighteen dioramas, each one a different scene. They all have different tiny features—tiny furniture, tiny windows, tiny doors. Each one depicts an unexplained death.

When you look at a Nutshell Study, you’re looking for clues about how the person or persons died. Was it a suicide? A homicide? An accident? The Nutshell Studies were designed 70 years ago by a woman to whom some refer as the “Godmother of Crime Scene Investigation.” Her name was Frances Glessner Lee.

Frances Glessner Lee was born in 1878 to a wealthy Chicago family. She was introduced to the world of death investigation through a family friend and pioneering medical examiner named George McGrath.

When McGrath would visit, he’d tell Lee about cases he was working on, and she developed her own fascination. Lee’s family didn’t support her interest in death investigation, so for years, she studied it quietly—reading, visiting crime scenes, and talking to experts. As she learned more, she became aware of various problems in the field.

Police would routinely botch investigations by unwittingly contaminating crime scenes. And beyond that, they didn’t know how to gather evidence from these scenes. They might not realize the significance of a pile of cigarettes or the positioning of a firearm. And autopsies either weren’t being done at all or were being done by doctors with no specific training in forensics.

When Lee’s parents and her brother passed away, Lee was in her fifties, and finally had access to the family money, and agency to do what she wanted.

In 1936 she gave a large sum of money to Harvard University to establish the first program of legal medicine. The program trained doctors to become medical examiners. In 1945, Lee started and presided over week-long training seminars to teach police how to gather clues from a crime scene.

Given that it was logistically and legally impossible to visit real crime scenes during the training seminars, Lee decided she would build miniature death scenes for the police to study. Each one would be based on a real death.

Each Nutshell Study also came with some basic information such as statements from whoever discovered the body, and other details police might normally have when arriving on the scene.

Frances Glessner Lee would come up with the concept and the design of each Nutshell Study, and her carpenter would then draw up the blueprints on the scale of one inch to a foot. He built the structures exactly the way you would a real, full-size room, with real studs and real doors with locks that worked.

Lee handled all the figures and the textiles in the dioramas. She made the tiny rugs and drapes and clothes. She would knit the stockings using straight pins and could only work for a short time before her eyes would fatigue.

The figures in the nutshells also sometimes demonstrate rigor mortis, which is a post-mortem stiffening of the body, and lividity, which is the way the blood settles in the body after death. Both provide clues as to how and when a person died.

The detail in the nutshells is obsessive. In one, an ashtray overflows with tiny cigarettes made with real tobacco hand-rolled by Lee herself—each one lit and then stubbed out.

Each diorama took about six months and about $6,000 to build—on par with the same amount of time and money it would have cost to build a real house in the 1940s. Lee felt that if the policemen saw any fault in them, they wouldn’t take them seriously. She wanted everything to be perfect.

Of course, Lee was always trying to be taken seriously in the all-male world she had entered. She was ultimately both respected and adored by the police that she worked with. They came to think of her not only as an expert in the field but also as a mother figure. She received stacks of cards from them on Mother’s Day.

The week-long seminars she led were thought to be the best training that homicide detectives could receive. And they’re still thought of that way today.

After Frances Glessner Lee died in 1962 the programs she funded at Harvard (including the week-long seminars) were ended, and the nutshells were put in storage, possibly headed for the trash. And then, Russell Fisher, the medical examiner in Baltimore and a former student of Lee’s programs at Harvard, stepped in and said Maryland would take over the seminars.

The Nutshells Studies were brought down to Baltimore in 1968, and are still used today to teach homicide investigation techniques.

In addition to her interest in improving crime scene investigation, Frances Glessner Lee promoted a system where every unexplained death goes through a scientific autopsy, performed by a medical examiner. She advocated that states abolish the coroner system in favor of a medical examiner system. She made some headway in the area, but many states are still on a coroner system.

Maryland has a state-wide centralized medical examiner system. Which means that anyone who dies unexpectedly in the state will get the same standard of investigation by medical doctors with forensic training. Bruce Goldfarb, the executive assistant to the Chief Medical Examiner in Maryland said he thinks that their office might be “the fullest embodiment” of Frances Glessner Lee’s vision.