1963 Unsolved Murder of Florence Kilsdonk, Black Creek

Florence Kilsdonk was Murdered on December 18, 1963

On December 18, 1963, Marvin Kilsdonk (29) returned to his Black Creek home after work to find his wife, Florence Kilsdonk (28), under the kitchen table in a pool of blood. She had been fatally stabbed nine times. Their 2-month old son was on top of the table, unharmed. It was reported that she was not sexually assaulted, and that it did not appear to be a robbery. The case remains unsolved.

Florence Kilsdonk
Florence Kilsdonk

Note: The information on this site is not intended to point to a particular suspect, but merely sum up the information that has been reported about the case. As noted in Marvin Kilsdonk’s January 1964 letter (through his attorney), “All of this, naturally, has had a cruel effect on his parents and family.” It is not the intent of this site to accuse anyone, or create additional anguish for the Kilsdonk family.

Florence (Rosenthal) Kilsdonk

Florence Rosenthal was born on October 15, 1935 in Kaukauna, WI to Edwin and Cecelia (Fox) Rosenthal. She graduated from Wrightstown High School, and was employed at Appleton Juvenile Furniture Company. On July 11, 1956, Florence (20) married Marvin Kilsdonk (21) at Holy Cross Catholic Church in Kaukauna. Their wedding reception was held at Van Abel’s in Hollandtown, and they honeymooned at Niagra Falls. Marvin was a St. John High School graduate, and was employed at Gears Dairy in Menasha at the time of their wedding.

Prior to living at their home in Black Creek, the Kilsdonks lived in Menasha where they had converted their home into several apartments.

At the time of the murder, the Kilsdonks lived in Black Creek on 189 acres. Marvin had farmed in the past with his brother, but the partnership dissolved in 1962. Marvin switched from dairying to growing cash crops, and rented out some of the land. He also had a full-time job as a dairy truck driver delivering milk in Menasha.

The Kilsdonks were members of St. Mary’s Catholic Church in Black Creek.

In June 1963, Florence left her job with a Neenah school supply firm in preparation for their son’s birth. Both Marvin and Florence were reportedly happy about the pregnancy as they had “waited a long time” for a pregnancy. Their son was born in October.

Florence Kilsdonk's Obituary
Florence Kilsdonk’s Obituary

Murder Overview

On the morning of her death, Florence and Marvin ate breakfast together prior to Marvin leaving for work at 4 am. He told police that Florence would sometimes go back to bed after he left. Their infant son was sleeping during their breakfast.

Marvin returned home from work around 2:30 pm, and found Florence under the kitchen table in a pool of blood. She had been fatally stabbed nine times. Their 2-month old son was on top of the table, unharmed.

Marvin went to Edward “Pat” Kettner’s home, a half mile away, to call the police, leaving his son behind. He burst into the Kettner’s kitchen shouting “Call the sheriff! My wife has been murdered!” Mrs. Kettner called the police, and then went with Marvin to his home, and cared for their son.

Lt. Zuelzke questions Marvin Kilsdonk, who is holding his infant son
12/18/1963: Lt. Zuelzke questions Marvin Kilsdonk, who is holding his infant son

Marvin and his son stayed with his parents in Little Chute following the murder.

Florence was wearing a housecoat and a nightgown. Her glasses had been knocked to the side of her head, and she had lost one blue slipper near the archway from the anteroom.

She appeared to have been shucking peanuts at the kitchen table just prior to her murder. Marvin reported that Florence had planned to spend the day making holiday candy and cookies. Breakfast dishes were still in the sink, and the radio was on.

An autopsy revealed that she was not sexually assaulted.


December 18th: A rural Menasha man was interrogated. (Although it is not clear, this is likely the man who was seen sleeping in his car the morning of the murder near the farmhouse.)

12/18/1963: Outagamie County Sheriff Spice, Undersheriff Marx, and Lt. Zuelzke examine Florence Kilsdonk's body
12/18/1963: Outagamie County Sheriff Spice, Undersheriff Marx, and Lt. Zuelzke examine Florence Kilsdonk’s body

December 18th: An armed deputy stood guard in the farmhouse overnight, Wednesday into Thursday.

December 19th: The mobile state crime lab was at the murder scene.

December 19th: It was reported that authorities said that Marvin and two other people took lie detector tests at the Brown County Sheriff’s Department.

December 27th: Marvin went to the state crime lab in Madison at the request of laboratory officials to take a lie detector test, and other undisclosed requests. Lt. Zuelzke said that the examinations did not result in evidence that would charge Marvin with a crime.

December 28th: Marvin’s car was impounded for investigation.

January 11, 1964: It was reported that Marvin Kilsdonk hired attorney Edward Bollenbeck. A letter released through his attorney, and reported on by The Post-Crescent reads: “Marvin Kilsdonk has suffered a tremendous personal tragedy as a result of the brutal slaying of his wife. He has been under a severe emotional strain since that terrible event. He has cooperated fully and assisted the investigating authorities, to the best of his ability, in attempting to solve this crime. He has voluntarily submitted to two lie detector tests and to numerous interrogations by the sheriff’s office investigating team… [ellipsis from newspaper] In spite of this cooperation and even though they have taken possession of his home and automobile, they have not brought forth one scintilla of substantial evidence tending to link him in any way to the crime.”

February 18, 1964: District Attorney Schaefer, Coroner Kemps, Lt. Zuelzke, and Assistant Attorney General Platz had a meeting on how to proceed in the murder investigation.

June 8, 1964: A stainless steel steak knife was found in the lining of an overstuffed bedroom chair in the Kilsdonk’s Black Creek farmhouse by tenants who were renting the home. The blade was slightly bent, and there were stains near the plastic handle. It was found by the tenant when she was looking for lost coins that she had dropped behind the cushion. The chair and other furniture belonged to the Kilsdonks.

June 9, 1964: The knife was turned over to the Sheriff’s Office, and they sent it to the crime laboratory.

June 10, 1964: The bedroom chair where the steak knife was found was taken, via warrant, by the Outagamie County Sheriff’s Department.

July 16, 1964: Outagamie County Sheriff Calvin Spice shared findings from the crime lab regarding the knife. The knife had some animal or fish blood and bits of fish scales on it. Spice also said that the knife was not one that would typically be carried in trouser pockets. It was described as being similar to other knives found in the home.

Kilsdonk home

Evidence and Information

  • Outagamie County Coroner Bernard Kemps placed the time of death between 7am and 8 am.
  • Police noted that upon their arrival, the front door was locked.
  • Police think Florence knew the assailant as she usually kept the door locked.
  • A bloody handprint was on their son’s blanket – police concede it may have innocently come from Marvin when he picked up his son.
  • A bloody handprint was found on the doorknob.
  • $200 had not been taken from on top of the bedroom chest.
  • Other rooms did not have signs of a struggle.
  • A “heavy hunting knife” was said to be the murder weapon, but it was not found at the scene. Outagamie County Sheriff Calvin Spice said that several knives “found elsewhere” have been sent to the lab.
  • Spots of blood were found in an outbuilding on the farm, 50 feet from the farmhouse.
  • Hair had been found in Florence’s hand.
  • It was reported that the newspaper “unofficially” learned that “several bloody objects” were found in the outbuildings.
  • One neighbor mentioned that someone went into her (the neighbor’s) garage, and left the car light on early in the morning on the day of the murder.
  • It was reported that people found it odd that Marvin went to Pat Kettner’s house to call the police as he had to pass other houses first. They wondered why he didn’t stop at one of those houses? Mrs. Kettner allegedly asked Marvin, and he said that their family’s name popped into his head, and he headed there.


In 2005, the Outagamie County Sheriff’s Department re-reviewed evidence in the case. Based on a search of news reports, it does not appear that they were able to solve this case.

Marvin Kilsdonk died at age 85 on June 19, 2020 in Chilton.


  • The Post-Crescent, July 11, 1956: https://www.newspapers.com/image/396151801
  • Green Bay Press-Gazette, December 19, 1963: https://www.newspapers.com/image/189304241
  • Green Bay Press-Gazette, December 19, 1963: https://www.newspapers.com/image/189304269
  • The Post-Crescent, December 19, 1963: https://www.newspapers.com/image/287541000
  • The Post-Crescent, December 20, 1963: https://www.newspapers.com/image/287544432
  • The Post-Crescent, December 20, 1963: https://www.newspapers.com/image/287544979
  • The Post-Crescent, December 27, 1963: https://www.newspapers.com/image/287554886
  • The Post-Crescent, December 28, 1963: https://www.newspapers.com/image/287556717
  • The Post-Crescent, December 28, 1963: https://www.newspapers.com/image/287558381
  • The Post-Crescent, January 9, 1964: https://www.newspapers.com/image/287569725
  • The Post-Crescent, January 11, 1964: https://www.newspapers.com/image/287572455
  • The Post-Crescent, June 11, 1964: https://www.newspapers.com/image/290661069
  • The Post-Crescent, June 11, 1964: https://www.newspapers.com/image/291045572
  • The Post-Crescent, December 18, 2005: https://www.newspapers.com/image/290667968
  • The Post-Crescent, December 18, 2005: https://www.newspapers.com/image/290668186/

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