A Remote Idaho Home and a Calculated Intruder
In May 2005, a small home near Lake Coeur d’Alene in northern Idaho became the target of a carefully planned home invasion.
By the time authorities discovered what had happened inside, three family members were dead, and two children were missing.
The crime would lead investigators to one of the most disturbing cases in Idaho’s history and expose a predator whose online writings hinted at the violence he was planning.
Case Snapshot
- Location: Rural home near Lake Coeur d’Alene, Kootenai County, Idaho
- Date: Murders discovered May 16, 2005
- Victims in the home:
- Brenda Groene, 40
- Mark McKenzie, 37
- Slade Groene, 13
- Kidnapped children:
- Shasta Groene, 8
- Dylan Groene, 9
- Primary offender: Joseph Edward Duncan III, registered sex offender and later convicted serial killer
- Status: Duncan convicted in state and federal courts; given multiple life sentences and federal death sentences, died on death row in 2021.
The Groene Family Home
The Groene family home sat off a rural road east of Coeur d’Alene, near the water and surrounded by trees.
Brenda Groene lived there with her children, and her boyfriend Mark McKenzie often stayed at the house.
To neighbors, it was one more modest home in a quiet part of northern Idaho.
But to Joseph Edward Duncan, it became a target.
Duncan was a convicted sex offender with a long history of offenses against children.
In the months before the attack, he had been out on parole and had reportedly spent time in the region, watching and planning.
May 16, 2005: A Home Invasion Turns Deadly
On May 16, 2005, deputies from the Kootenai County Sheriff’s Office went to the Groene home for an unrelated check.
What they found inside was far worse than they expected.
The bodies of Brenda Groene, her boyfriend Mark McKenzie, and her 13‑year‑old son Slade were discovered in the house.
They had been bound and beaten to death. The scene made it clear that the attack had been deliberate and brutal.
Two younger children — 9‑year‑old Dylan and 8‑year‑old Shasta — were missing.
What looked at first like a triple homicide was now also a kidnapping, and time was working against them.
Authorities believe Duncan had entered the home in the early morning hours, armed with restraints and a weapon, and had killed the adults and Slade in order to take the younger children.
For investigators, it was a chilling example of a predator willing to wipe out most of a household to get to two kids.
A Community Searches for Two Children
The murders and abductions shook northern Idaho.
Photos of Dylan and Shasta were circulated widely, and news coverage spread far beyond the region.
Search teams and investigators worked multiple angles:
- Could the children still be close by?
- Had they been taken out of state?
- Was this connected to Duncan’s past offenses?
While investigators worked behind the scenes, the public saw only that a family had been destroyed and two children had vanished.
Captivity in the Wilderness
In the weeks that followed, Dylan and Shasta were taken to remote locations in Idaho and Montana, including primitive campsites.
There, Duncan repeatedly abused them and controlled every aspect of their environment.
Shasta would later tell investigators and a jury that Duncan talked to her about what he had done to her family, telling her he had beaten them to death so he could take her and Dylan.
She also recounted how, at a remote campsite, he shot and killed Dylan.
For nearly seven weeks, no one knew exactly where Duncan and the children were.
Outwardly, the case looked stalled; inwardly, law enforcement hoped for any break that could bring Shasta and Dylan home.
July 2, 2005: A Denny’s Waitress Notices a Child
That break came from an ordinary place: a Denny’s restaurant in Coeur d’Alene.
In the early hours of July 2, 2005, a waitress noticed a girl sitting in a booth with a man.
The girl looked like the photos of Shasta Groene that had been on the news for weeks.
Staff quietly compared what they were seeing to the missing‑child images.
Convinced it was her, they called police and tried to keep the pair from leaving, offering refills and stretching out the meal.
When officers arrived, they confirmed that the girl was Shasta and arrested the man with her: Joseph Edward Duncan.
The rescue of Shasta at that Denny’s ended her captivity and opened the door to understanding everything that had happened since the night of the home invasion.
Connecting Duncan to Other Crimes
After his arrest in Idaho, Duncan quickly became a suspect — and later a defendant — in multiple cases.
He was charged in Idaho state court with three counts of first‑degree murder for the killings of Brenda, Mark, and Slade, and kidnapping related to the events at the Groene home.
In federal court, he faced charges for the kidnappings of Shasta and Dylan, the sexual abuse, and Dylan’s murder.
During the investigation, authorities also linked him to earlier unsolved cases, including the 1997 abduction and murder of 10‑year‑old Anthony Martinez in California and the murders of two girls, Sammiejo White and Carmen Cubias, in Washington.
In total:
- Duncan received multiple life sentences in Idaho and California.
- In federal court, he was given three death sentences plus additional life terms for crimes related to Dylan’s kidnapping, abuse, and murder.
- He died on federal death row in 2021 after being diagnosed with brain cancer.
“Demons” on a Blog: Disturbing Writings Before the Crimes
One of the most unsettling aspects of the case is what Duncan wrote online before the Groene murders and kidnappings.
Using a blog he called “Blogging the Fifth Nail,” Duncan wrote about his “demons,” his struggle with right and wrong, and dark fantasies about violence.
In entries posted just days before the abductions, he described feeling as if his demons had taken over and questioned whether it would be “right or wrong” to take others with him into destruction.
At the time, the blog looked like the ramblings of a troubled man.
Only after the Groene case broke did readers and investigators realize how close those posts were to the crimes he would commit.
The existence of that blog underscores a chilling truth: sometimes, the warning signs are visible, but no one can see how imminent the danger really is.
Why This Case Is on True Crime Maps
The Groene family case is defined by place:
- A rural Idaho home near Lake Coeur d’Alene where a family went to sleep and a predator broke in.
- The remote campsites in the forests and mountains of Idaho and Montana where two children were held.
- A Denny’s restaurant in Coeur d’Alene, where alert staff helped end a nightmare.
On True Crime Maps, the pin for this case marks the Groene home — the starting point of a crime that moved across county and state lines but began as a home invasion in the middle of the night.
It’s a reminder of how vulnerable a family home can be when someone with a long history of violence decides to target it, and how one act of awareness — a waitress recognizing a child in a diner — can make the difference between tragedy and survival.
