The Yule Bomber

At the close of 1922, Wood County, Wisc., was like any other rural Midwest county where people made their living off the land. Aside from a little problem with bootleggers and a controversial drainage project, Wood County was a quiet place where people worked hard and followed the Golden Rule. It was the last place anyone would expect to host a murder trial that would become one of the defining moments of forensic science.
The year had been a contentious one for the County Commission. The first issue Commissioner James Chapman and the board had to contend with was an attempt to curtail the rise in bootlegging activity in the county. It voted in an unpopular and draconian ordinance to punish anyone connecting with violating Prohibition laws and provided an additional $5,000 appropriation for the sheriff to enforce the law. The board was making it clear to everyone from the organized bootlegger to the farmer who ran a small still that Prohibition was the law of the land and that Wood County would brook no violation.
The drainage project, however, made the controversy over the Prohibition ordinance pale in comparison.
For years farmers and landowners had struggled with controlling the flooding of the Wisconsin River which meandered through the county. The Wisconsin, which has its head somewhere near the Wisconsin/Michigan border and flows into the Mississippi, was a major thoroughfare for the lumber industry which dammed the river here and there to ensure a heavy flow of water as the lumber jacks floated their logs to the paper mills downstate. Those dams altered the natural flow of water from the northern snows, causing problems for farmers whose fields would often suffer from overflows.
In an effort to control the flood waters, the Wood County Commissioners had approved a plan to dredge a series of drainage ditches across the county, cutting through farmland. The plan to encroach across the private property of fiercely independent farmers was unpopular enough, but when the Board decided to pay for the project and its perpetual upkeep through new taxes on the affected property owners, the complaints increased tenfold.
No one protested more than John Magnuson, a Swedish immigrant who came to Marshfield, Wisc., by way of Chicago and South Africa.
Magnuson was a 44-year-old farmer and machinist who spoke only broken English and who lived on his farm with his wife and two teenage children. He had no use for some stranger digging drainage ditches on his property, even less use for new taxes, and made no secret of the fact that he was not opposed to violence to stop the project.
Once, when approached by neighbors asking him to sign a petition against the project, Magnuson told them he planned to “peck, peck, peck against the head man” of the project with his rifle.
Magnuson was the prime suspect in the summer of 1922 when a dredge working on the project exploded in a fireball near his property. The dredge was loaded with 100 gallons of gasoline and an equal amount of diesel fuel when it exploded in the middle of the night. Although TNT was being used as part of the dredging project, the explosive was housed several hundred yards away.
Few people believed that the blast was an accident but investigators were unable to prove conclusively that the dredge was sabotaged.
In the fall of that year Magnuson approached the drain commission to protest the ditch assessment he received. The discussion quickly turned ugly. He threatened a lawsuit, then claimed Chapman was accepting bribes from the firms digging the ditches. Finally, Magnuson threatened violence.
Chapman responded that he would “make it hot” if Magnuson continued to assert he was on the take, but promised to review Magnuson’s assessment.
“He certainly was earnest about the use of violence,” Chapman said he believed at the time.
Later the two men — who openly considered the other to be an enemy — met again.
“I saw Mr. Magnuson in the fall and told him the assessment was fair and it could not be changed,” Chapman said later. It was the last time the men would talk.
Winter came and work on the ditches stopped, but apparently Magnuson continued to seethe.
Two days after Christmas 1922, postal carrier Eugene Fehrenbach was delivering mail to the Thorbald Moen farm and picked up a tubular package wrapped in heavy gray paper and tied with a string resting atop the Moens’ mailbox. The package contained no return address and in a semi-illiterate hand was addressed to “J.A. Chapman, R.1 Marsfilld Wis.”
Fehrenbach assumed the package was meant for James Chapman whose address was Route 1, Marshfield. He passed the mail along to the Route 1 postman, John Heaton, who delivered it to the Chapman home, where James Tarr, Chapman’s grandson passed it along to his grandmother, Clementine, 60.
Since Christmas had just passed, the Chapmans thought the package, 12 inches long by 1.5-inches wide and 1-inch high, was a belated gift and the family gathered around as James Chapman opened it.
As he cut the third string, the pipe bomb inside the package exploded with sufficient force to blow four fingers off his left hand, leaving his little finger hanging from his wrist by the skin. His left leg, on which the bomb sat, was sliced open across the thigh.
Across from him, Clementine Chapman screamed that she was hit and was dying. She staggered from the room and collapsed on a bed, mortally wounded. She had been hit in the head by wood and metal shrapnel from the bomb, but the most serious wounds were to her torso, which had borne the brunt of the explosive force.
Tarr, standing behind his grandfather, suffered minor injuries. In shock, he ran to the telephone, screaming “for God’s sake, come quick!” over and over into the party line.
By the time help arrived, James Chapman had managed to crawl to his wife, but there was nothing that could be done for her. She died in the Marshfield hospital the next day, about the time doctors were amputating what was left of Chapman’s left hand. Surgeons were unable to remove a shard of iron that had embedded itself in Chapman’s leg — he would have it there for the rest of his life, just one reminder of the attack.
The force of the explosion drove the pocket knife Chapman used to cut the strings 2 inches deep into the wood floor and investigators later counted 40 holes in the walls caused by wood and metal shards.
It did not take experts from the U.S. Treasury Department and Postal Inspectors long to piece together the composition of the bomb that killed Clementine Chapman. It was fueled by picric acid, one of the earliest synthesized explosives, more powerful than TNT, and something readily available in a farming community like Wood County. The explosion was set off by the primer portion of a shotgun shell which ignited a detonator cap. A spring-loaded trigger made from a wagon bolt that struck the primer was connected to one of the strings binding the package. The bomb itself was an brass pipe encased in a white elm “shell.” For shrapnel the bomber had used bits of brass and iron.
Although the explosion was sufficient to kill one person, critically injure a second, and give a third minor injuries (Tarr received a cut above one eye), there was enough of the gray wrapping paper left to allow investigators to study the handwriting of the sender and the presumed bomber.
Just as it didn’t take investigators long to piece together the bomb, it didn’t take long for them to decide on their prime suspect. While there was some half-hearted speculation initially that the bomb came from bootleggers in the area who were unhappy with James Chapman’s crusade against the illegal stills that dotted the county, police made it clear that they wanted very much to talk to John Magnuson.
On December 29, 1922, in what was the largest funeral anyone in the area could remember, the people of Wood County buried Clementine Chapman. The mood was ugly and there were more than a few people talking about a lynching. Posses of lawmen, citizens, and newsmen who had flocked to the small city of Marshfield fanned out across the area in search of Magnuson. Perhaps fortunately for him, Magnuson was arrested by Sheriff Walter Mueller and his undersheriff, Cliff Bluett.
On January 4, 1923, Magnuson, protesting his innocence, was bound over for trial on first degree murder charges.
The investigation and trial would turn out to be one of early forensic science’s defining moments. In an era when fingerprint evidence was just beginning to be used in the courtroom, the guilt or innocence of John Magnuson would hang on whether prosecutors in a small Wisconsin county could convince a jury to believe the testimony of forensic linguists, handwriting analysts, ballistics experts, and chemists.

The Linguistic Evidence

Forensic Linguistics is one of the most fascinating applications of a so-called “soft science” to the law. Linguistics is the scientific study of language; while forensic linguistics is the application of the observations of this study to the law. In other words, how words, speech, syntax and other parts of language can be used as evidence in a court.
In the Magnuson case, Professor J.H. Stromberg of the University of Minnesota was called by the prosecution as an expert witness in the Swedish language.
Stromberg examined the scrap of paper left from the bomb wrapper that contained the address “Marsfilld” rather than the correct spelling, “Marshfield.”
A Swede, he explained, would pronounce “Mars” as “Marsh,” and an “uneducated” Swede would spell “field” as “filld, or fild.” Thus it could be reasonably inferred that an “uneducated Swede” would spell “Marshfield” as “Marsfilld.”
Following up on this testimony, the arresting officers presented handwriting exemplars from Magnuson in which he wrote the word “Marshfield” five times. Each time Magnuson left out the H and the E. Later, after he employed an attorney, he correctly spelled “Marshfield.”
Although this evidence was interesting and possibly damning, it only showed that someone with knowledge of Swedish addressed the package containing the bomb. Unfortunately for Magnuson, he was the only known Swede in the area with a motive to attack Chapman.

The Handwriting Analysis

Magnuson’s handwriting, along with the evidence from the scene, was submitted to three experts: John F. Tyrrell, Albert S. Osborn, and Jay F. Wood. These three men were at the time the giants in the field of scientific handwriting analysis. Osborn was the author of the field’s bible, Questioned Documents, and would in a few years testify as an expert for the prosecution in the trial of Bruno Hauptmann for kidnapping the Lindbergh baby. He also served as the first president of the American Society of Questioned Document Examiners.
Osborn, often cited as “the father of handwriting experts,” noted 14 points of similarity between Magnuson’s exemplars and the bomb wrapper. Osborn’s testimony centered on the small letter f in the word “Marshfield,” which he said was “unusual in its significance and peculiarity” because of the downward stroke of the cross characters on the f’s in the sample.
He also noted several examples of “overwriting” and “remarking and improving” the letters.
Ticking off the points that are nearly invisible to the uninitiated, Osborn noted the bending of the capital A, the “patching” of the letter c, and the formation of the small a. The W’s also demonstrated similarities, as did the small s’s.
Not only did the letters themselves tend to indicate that the same person wrote them, the spaces between them also pointed to a single author, Osborn said, referring to the distance between the J and the A and the C and h.
Equally telling are the consistent dots at the top of the letter a, he said.
Working separately from each other and Osborn, Tyrrell and Wood also identified the writing on the bomb wrapper as Magnuson’s.
The defense attempted to cast doubt on the experts’ work by asserting an “accidental coincidence,” but their own expert, on cross-examination, proved to be so damaging that he might have been called by the prosecution.
The best the defense could do was have its expert assert “It is easier to prove a person didn’t write a certain document than it is to prove a person did write a certain document.”

The Pen, Ink and Glue

The writing was also examined from the point of view of its physical formation. Commonly used ball point pens were not invented until 1935, so it was obvious that the address had been written on the package by fountain pen. Analysis by the handwriting experts showed that the pen that wrote the address was a round-point pen of medium size. Police found a similar pen belonging to Magnuson’s daughter in his home.
While the ink in the pen gave off the same spectral signature of the ink on the wrapper, there was no ink in the Magnuson home that matched either.
Probing further, investigators learned that Magnuson’s daughter lent her pen to a classmate who refilled and returned it with black ink, rather than the blue ink found in the Magnuson home. Combining the two inks as a control created the identical spectral signature.
The glue used to hold down the string linked to the trigger was determined by analysis to be “LePage’s Glue.” The same glue, with the same chemical make-up was used to fix another pen in the Magnuson house.

The White Elm

Professor Arthur Koehler of the United States forest products laboratory at Madison testified for the State that sawdust taken from Magnuson’s work bench was of white elm. This would not have been significant had not Magnuson denied that he had ever worked on elm wood in his shop in his life.
He admitted having worked on oak. Under the microscope it appeared that the sawdust came from hemlock, oak, and white elm. That part of the wooden covering of the bomb which remained was white elm.

The Trigger

During the search of Magnuson’s workshop, a triangular “trip or trigger” was taken off a gasoline engine on account of its resemblance to the trigger found on the bomb.
The trigger on the bomb was compared with the trigger taken from the gas engine by Professor David Fahlberg of the University of Wisconsin. His analysis showed that the trigger from the bomb had the identical crystals and formation of that obtained from the trip on the gasoline engine. The surface of the two pieces appeared to be identical.
“The thickness was the same to one-half part of a thousandth of an inch,” Fahlberg said. “The angle of the cut of the two pieces was the same to within one tenth of a degree.”
In addition to the scientific evidence, the prosecution presented other circumstantial evidence linking Magnuson to the crime: shotgun shells identical to those used as the igniter in the bomb were found in the Magnuson workshop, pipes with the same thread count as those found in the bomb — an unusual 18 to the inch size — also turned up in the search.

The End

The jury considered the evidence over 12 hours before returning a first-degree murder conviction. Magnuson, still asserting his innocence, was sentenced to life in prison.
In the early 1930s Magnuson was declared insane and committed to the Wisconsin state hospital. He managed to walk away from the hospital in 1940 and was on the loose for 4 years until he was captured in Chicago and returned to prison. He was paroled in 1952 on the condition that he leave Wisconsin. He died in Grayling, Michigan at the age of 78 four years later.