Two Decades Ago Jürgen Knemeyer was Beaten to Death and His Murderer Walks Free

During the late summer of 1999, Jürgen Knemeyer lived in Willits on Hilltop Drive. He was a long-time resident of Mendocino County–helping raise his daughter, working as a journeyman at Ukiah’s California Tile, and supplementing his income by cultivating marijuana. On August 14th, 1999, Mendocino County Sheriffs were dispatched to his residence after a neighbor reported his doors were left open for an inordinate amount of time. When deputies arrived, they found him savagely beaten to death. To this day, his murderer has yet to be brought to justice.

Jürgen and his daughter Sabrina Knemeyer. [Photo from Sabrina Knemeyer, Jürgen’s daughter]

Sabrina Knemeyer, Jürgen’s daughter, has lived with the pain of her father’s murder for the last twenty years. She still resides in Mendocino County and hopes sharing his story could elicit information that would solve this decades-old crime. Jürgen’s death has rippled throughout his family tree: “his other family & siblings have lived with the pain of not knowing. Three of his siblings have passed on not ever knowing.” Sabrina remembers her father’s gentle soul, his passion for balsa model airplanes, and the demonstrable love he had for her.

he Knemeyer’s seven children. Jürgen is in the middle. Photo from Sabrina Knemeyer, Jürgen’s daughter]

Jürgen was born in Germany on October 15th, 1942. He was the middle child of seven. His family relocated to the United States in 1947 because of Operation Paperclip, an American military program to recruit German scientists to gain military advantage over the Soviet Union. Jürgen’s father was Siegfried Knemeyer who was the Head of Technical Development at the Reich Ministry of Aviation of Nazi Germany during World War II. Seigfried was contracted to work for the United States War Department and later was awarded the U.S. Department of Defense Distinguished Civilian Service Award.

Photo of Siegfried Knemeyer, Jürgen’s father. [Public Domain photograph from the United States National Archives and Records Administration (NARA)]

When the Knemeyers immigrated to the United States, they settled in Yellow Springs, Ohio. Upon graduating from John Bryan High School, Jürgen moved to California’s Bay Area and attended Berkeley Community College. In Berkeley, he met his first and only wife Margi and they bore their daughter Lisa. He met Sabrina’s mother Lynne in 1969. Sabrina was born in 1971 and five years later moved to Willits with her mother. Hoping to maintain a relationship with Sabrina, Jürgen moved to Mendocino County in 1979 renting a cabin in Longvale where he began to cultivate marijuana.

According to Sabrina, he had lived on the Hilltop property where he died for over 10 years. He renovated structures on the property for the landlord.When characterizing her father’s involvement with the marijuana industry, Sabrina described how he was a “grower and seller”. He had connections with other cultivators throughout Northern California including Crescent City, Eureka, Laytonville, Covelo and throughout Mendocino County. He also “sold marijuana out of state”. Sabrina was never privy to the details of her father’s marijuana business because “he didn’t want me involved.”

Jürgen shows off one of his model airplanes. [Photo from Sabrina Knemeyer, Jürgen’s daughter]

Mike Moore, a retired tilemaker, used to work with Jürgen at California Tile. His father Craig Moore owned the business and recruited Jürgen. Mike saw Jürgen as “a father figure”. He described how Jürgen’s craftsmanship was done “with precision” and how “everything had to be perfect”. Mike would take his daughter to visit “Jurgey” as he was affectionately known and he would always have a hand-hewn doll or birdhouse for her.

Mike knew of Jürgen’s involvement in the marijuana industry. Mike helped him construct a grow house and drying barn. Jürgen was “doing something up north with some weed people”. Mike asserts Jürgen would “do anything for anybody” and was concerned “there were people taking advantage of him”. He hoped Jürgen would “get away from those people”.

Past reporting from the Ukiah Daily Journal offers details of Jürgen’s last days and the circumstances of his death. Neighbors reported the consistent foot traffic of visitors to Jürgen’s home. In the early hours of August 14th, a neighbor noticed a light shining through an open door of Jürgen’s home. Assuming all was well, the neighbor went to sleep and found the door in the same condition when they awoke. After approaching the open door and calling Jürgen’s name to no answer, 911 was called and Mendocino Sheriffs conducted a welfare check where he was found beaten to death. (Ukiah Daily Journal, August 16, 20, September 1, 1999, March 6, 2006)

The Tuesday following Jürgen’s death, deputies were investigating the crime scene when they discovered two Willits residents tending illegal marijuana growing operation near the Hilltop Drive property. Past reporting has suggested a connection between these arrests and Jürgen’s murder. At the time of the article, MCSO had declined to comment on any connection between the arrests and Jürgen’s death.

The presence of marijuana at the Hilltop property came as a surprise to his daughter Sabrina. She had known her father to always keep his cultivation on properties far away from where he lived but found a small clone room at the Hilltop property. She claimed this was the “first time I knew of that he crossed lines.”

Jürgen as a younger man holding his daughter Sabrina. [Photo from Sabrina Knemeyer, Jürgen’s daughter]

When discussing her father’s murder, Sabrina thought it inconceivable that anyone could demonstrate such violence towards her father. She was informed of her father’s death after returning home from a babysitting job when she “got a voicemail from a friend who seemed upset. She told me the whole house had been taped off.”

Mendocino Sheriff’s Public Information Officer Gregory Van Patten provided information about the agency’s handling of Jürgen’s case. Van Patten vividly remembered the case because when the murdered occurred he was “1.5-2 years” into his career as an investigator.

Van Patten explained the particulars of the case could not be discussed because these details could compromise the investigation. However, he did offer that in 2011 MCSO requested the assistance of the California Department of Justice in analyzing biological and latent evidence found at the scene of the crime. The genetic information garnered from these samples could be used to match them against suspects of Jürgen’s murder.

Please consider reaching out to others in the community, because, as Van Patten noted, “The minute people stop talking, the case becomes harder to solve. The more that the public is educated on these cases, the more people share their experiences.”

Essential Questions about the Case

  • Who were the visitors that neighbors reported coming and going from Jürgen’s home in the weeks preceding his death?
  • What circumstances led Jürgen to “cross lives” and cultivate marijuana at his home?
  • Emerald Triangle cultivators: did you know Jürgen? How did you know him? What was your relationship like with him? Why would someone have it out for him?

If you know anything about the murder of Jürgen, email us at, message us via Facebook, or call in a tip at (707) 560-1543. Other reporting options include the Mendocino County Sheriff Office’s Tip-Line (707-234-2100) and the WeTip anonymous crime reporting hotline (800-782-7463).

Cold Case Mendocino works hard to tell the story of the missing and murdered. If you appreciate our efforts, please consider donating.

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