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...[T]he world will know who I really was, and what I really did... I am scared, alone, and confused, and my reaction is to strike out toward the perceived source of my misery, society. My intent is to harm society as much as I can, then die.

Joseph Edward Duncan III was an American convicted pedophilic and ephebophilic serial rapist, abductor, arsonist, and later serial killer, family annihilator, and stalker. He is infamous for the 2005 murders of several members of the Groene family and abductions of the two youngest children, one of whom he later killed.


Joseph Duncan

Early mugshot of Duncan.

Duncan was born on February 25, 1963, the fourth of five children and oldest son into a military family at Fort Bragg Military Base in North Carolina. With his dad in the army, he and his four siblings moved frequently around the US and even other countries, eventually settling in Tacoma, Washington, where he was raised during his teenage years. In 1978, at the age of 15, he committed his first known sex crime, raping a nine-year-old boy at gunpoint, which he was arrested for. The following year, he was arrested again for driving a stolen car. Sentenced as a juvenile, he was sent to Dyslin's Boys' ranch, where he was assigned to hold meetings with a therapist. It was during this time that his parents divorced, causing his father to remarry, and his three older sisters moving out at once. Released after a few months, Duncan stole several guns from a neighbor in 1980, later abducting, raping, and sodomizing a 14-year-old boy at gunpoint, later getting caught and sentenced to twenty years in prison. In 1994, fourteen years after his sentencing, he was paroled under the condition that he would not engage in any interaction with minors.

Initially sent to a halfway house, Duncan began living in other locations in the Seattle, Washington area, and eventually violated his parole two years later, being arrested for marijuana usage and firearm possession. He was sent to jail for a full month but was paroled again, with newer restrictions. During his parole, it is believed that he murdered ten-year-old Anthony Michael Martinez of Indio, California, in 1997, as well as his alleged and suspected victims. On March 31, 1997, Duncan violated his parole again by stealing his girlfriend's car and traveled abroad, but was later arrested on August 27 at his half-sister's house in Kansas City, Missouri, and returned to prison. However, he was again released from prison, on July 14, 2000, for good behavior, and Duncan moved to Fargo, North Dakota. On July 3, 2004, Duncan molested a boy at a Detroit Lakes, Minnesota playground and tried to do the same to the boy's friend, for which he would be arrested and charged with on March 2005. A Fargo businessman who was an acquaintance of Duncan's helped him post his $15,000 bail, and Duncan was released from custody on April 5.

Groene Murders and Abductions[]

"I got out and I got even. But I did not get caught. So I got even again, and again did not get caught. I got even twice [actually more]."

Groene house

The Groene house where the bodies of Brenda and Slade Groene and Mark McKenzie were found.

Sometime before skipping bail, Duncan apparently made travel plans. According to police investigations, he first stopped by at a Wal-Mart to buy night-vision goggles and a video camcorder. Then, he rented a red 2005 Jeep Grand Cherokee on April 15, which he used to travel through parts of Missouri. On April 27, he stole a set of license plates from another vehicle in Missouri's Newton County, and a week later, on May 4, the Jeep was reported as a stolen vehicle. On June 1, a federal warrant was issued for Duncan's arrest for not showing up at his trial. At that point, he had taken Interstate 90, either through South Dakota or Wyoming, and headed west into Idaho. There, he stopped at the Wolf Lodge area, approximately eight miles west of Coeur d'Alene, for unspecified reasons.

From there, he apparently wound up at a neighborhood located near Coeur d'Alene, where he spotted the Groene family, consisting of 40-year-old Brenda Groene; her 37-year-old boyfriend Mark McKenzie; and Brenda's three children, 13-year-old Slade, nine-year-old Dylan, and eight-year-old Shasta. Becoming interested with Dylan and Shasta, Duncan repeatedly returned to the neighborhood to secretly watch the two children from a safe vantage point, using his night-vision goggles during the nighttime. He is also said to have stalked the Groene family for days as he prepared for the attack. On May 15, the family drove to Coeur d'Alene to run errands before returning to celebrate a barbecue with others, which went into the evening hours. According to a report that appeared in The Spokesman-Review, Slade Groene had been hired by a neighbor to mow the grass by his driveway earlier that day; the neighbor didn't have enough money to pay Slade but promised him that he would stop by his house tomorrow to pay the money.

When the neighbor arrived at the Groene home on May 16 to pay Slade, he found that no one was apparently home, a dog was barking incessantly from inside, and the family cars were still parked in the driveway but with their doors opened. Out of suspicion, the neighbor called 911. When deputies arrived, they found the bodies of Brenda and Slade in the kitchen and Mark McKenzie's body in the living room; all three were bludgeoned to death. There was no sign of Dylan or Shasta Groene. Immediately, the deputies sealed off the house and closed off the road in the vicinity of the house, designating the entire area a crime scene. The following day, coroners officially identified the three bodies in the house, and they were systematically removed from the scene to be taken to the county morgue. Meanwhile, a search effort for Dylan and Shasta was launched, with volunteers from the Kootenai County Search and Rescue searching throughout the wooded areas surrounding the Groene-McKenzie house and also Lake Coeur d'Alene; an AMBER Alert was also issued nationwide.

On May 18, a person of interest surfaced in the case: 33-year-old Robert Roy "Concrete Bob" Lutner, a worker in the concrete and construction industry (hence the nickname) with a somewhat lengthy criminal record, who was believed to have visited the family on the day of the murders, just hours before; a relative of his told investigators that Lutner owed Brenda Groene and Mark McKenzie $2,000. Upon learning that police were searching for him, he turned himself in and denied having to do anything with the murders. Lutner then took a polygraph test and passed, taking himself out of any suspicion as a result. During the search and investigation, the FBI and other local agencies joined in, with the former offering a $100,000 reward for information leading to Dylan and Shasta's safe recoveries. The case quickly became the largest criminal investigation in the history of Kootenai County.

Discovery and Arrest[]

Duncan Shasta footage

Security footage of Duncan and Shasta that led to the former's arrest.

On May 19, investigators received a tip from a sporting goods store owner in Bonners Ferry, Idaho, about a man asking for directions to Libby, Montana, driving a white van with Washington license plates and accompanied by two children who fit Dylan and Shasta's physical descriptions. Though all of the roads leading from Bonners Ferry to Libby were searched, no sign of the van was found. Meanwhile, investigators discussed the possible motives of the killings being because of a drug deal gone bad, since marijuana and methamphetamine were found in Brenda and Mark's bloodstreams during their autopsies, or even gang-related, leading police to bring in a gang unit from Spokane, Washington, for interrogation. However, none of these motives fit, and no new information developed in the investigation.

Then, at about 1:30 p.m. on July 2, 48 days after the case began, Duncan and Shasta were spotted in Coeur d'Alene's Denny's restaurant by two young men smoking cigarettes outside. One of the men recognized Shasta from a billboard that he passed earlier that evening and alerted his girlfriend and several employees, some of whom had already recognized Shasta. The manager called 911 at 1:51 p.m. and police eventually arrived at the restaurant. Duncan placed Shasta in the restrooms for unspecified reasons and returned a few minutes later, only to be arrested. Shasta was rescued and taken to a local hospital for a couple days, where she was deemed to be in good physical health. However, there was no trace of Dylan anywhere in the restaurant or the red Jeep Cherokee Duncan was driving at the time of the arrest. Recovered from the Jeep were dark gloves, the night-vision goggles, a video camcorder, a 12-gauge shotgun, and a red shotgun shell.

Trial, Incarceration, Aftermath, and Death[]

Duncan in court

Duncan in court.

Using details given by Shasta, authorities located a Montana campsite where Duncan held her and Dylan captive. Two days after Shasta's rescue, officials gravely announced that Dylan's remains were found off of a remote Forest Service road in the Bitterroot Mountains; an autopsy confirmed that he had been shot to death and burned afterwards. Police also discovered a blog that Duncan had, which had implications that he claimed more lives. As a result, the FBI and investigators in at least five states began determining the timeline of Duncan's travels and corresponding it with any unsolved rapes and/or murders of children. Duncan first appeared in court on July 13, where he was charged with three counts of first-degree murder and three counts of first-degree kidnapping, all in conjunction with the deaths of Brenda and Slade Groene and Mark McKenzie. Plans of also charging him with abducting Shasta and Dylan by Kootenai County prosecutors were deferred to the federal court, since transporting children across state lines for the purpose of sexual exploitation was a federal offense.

Duncan's trial date was scheduled to begin on January 17, 2006, but it was pushed back to April 4 when First District Judge Fred Gibler positively responded to Duncan's defense attorneys' requests for more time to prepare for a trial. It was then pushed back again to October 26, and once it began, Duncan, working out a deal, pleaded guilty to all of the counts against him. By the terms of his deal with Idaho prosecutors, he was required to cooperate with Kootenai County investigators in the murder and abduction aspects of the case. Additionally, it was agreed that his guilty pleas couldn't be withdrawn, and if he wasn't convicted in similar pending cases in federal court, then Idaho was able to hold a request for the death penalty, in which Shasta would not be required to testify. Eventually, Duncan was sentenced to three consecutive life sentences without possibility of parole, pending the outcome of the federal cases against him.

On January 18, 2007, Duncan was indicted by a Coeur d'Alene federal grand jury on ten counts of "kidnapping, kidnapping resulting in death, aggravated sexual abuse of a minor, and sexual exploitation of a child resulting in death", as well as other crimes related to illegal firearm possession and grand theft auto. The trial date was pushed to January 22, 2008, when his defense attorneys requested a postponement; on December 3, 2007, Duncan pleaded guilty to all of the charges. On April 14, 2008, Duncan dismissed his attorneys and offered to represent himself. As a result, an evaluation was issued to determine his competency, and therefore his ability to represent himself; the evaluation determined that he was indeed competent enough to do so. On August 27, the jury recommended the death penalty after a few hours of deliberation, and the judge sentenced Duncan to three death sentences for "kidnapping resulting in death, sexual exploitation of a child resulting in death, and use of a firearm in a violent crime resulting in death", all of the charges referring to Dylan's murder. On November 3, he was sentenced to an additional three consecutive life sentences for abducting Shasta and sexually abusing her and Dylan. On July 2011, the Ninth Circuit Court of Appeals reversed the district court's decision to permit Duncan to represent himself without first holding a hearing over his competence to do so and remanded for a hearing. As of May 18, 2012, on remand, the district court hadn't yet set a competency hearing.

On January 18, 2007, the same day he was indicted in federal court, Riverside County officials announced that Duncan was charged with the murder of Anthony Martinez, who was confirmed by investigators to have been killed by Duncan as well after making a positive DNA match to a partial thumb-print discovered on duct tape found near Anthony's body. However, despite several attempts made by Riverside County officials to extradite Duncan to California, including an appeal by then-Governor of California Arnold Schwarzenegger, Duncan's federal trial proceeded. Eventually, on January 24, 2009, he was extradited to California five months after being sentenced to death by the federal court.

On March 15, 2011, Duncan pleaded guilty to Martinez's murder and was sentenced to two consecutive life sentences on April 5, 2011. As part of an issued plea deal, the sentence came without the possibility of parole or the right to make an appeal. Although Duncan faced the possibility of a separate death sentence for Anthony's murder in addition to the ones he had already received in federal court, Riverside County District Attorney Paul Zellerbach justified the life sentence, stating that he consulted with the Martinez family, who wanted closure and that "the federal system will kill him long before the state of California would have seriously considered it". Anthony's mother reacted critically upon finding out that Duncan had only served fourteen years of the twenty-year prison sentence he was given in 1980, which eventually led to the Groene-McKenzie murders; she said, "How do you get out for good behavior? Someone like that can't be rehabilitated. I don't care what psychologists say." Duncan was incarcerated at the United States Penitentiary, Terre Haute in Indiana. He died on March 28, 2021 from brain cancer, aged 58. His federal death sentence was not rescinded at the time of his death.

Modus Operandi[]

According to Shasta Groene, Duncan held the Groene family at gunpoint with a 12-gauge shotgun and used nylon zip-ties to restrain Brenda Groene, Mark McKenzie, and Slade Groene, all of whom he murdered by bludgeoning them to death with a FatMax claw-hammer. He also abducted, raped, and molested Shasta and Dylan Groene, the latter of whom he killed by shooting him and then burning his body post-mortem. According to TruTV Crime Library, he tortured Dylan by hanging him to the point of unconsciousness before reviving him. According to a confession that was given by Duncan, he molested Anthony Martinez as well and killed him by bludgeoning him with a rock.

Known Victims[]


Shasta and Dylan Groene

Shasta (left) and Dylan Groene (right).

Anthony Martinez

Anthony Michael Martinez.

The dates and locations denote when and where the victims were found

  • Unspecified date in 1978, Tacoma, Washington: Unnamed nine-year-old boy (raped at gunpoint, but not killed)
  • Unspecified date in 1980, Tacoma, Washington: Unnamed 14-year-old boy (abducted, raped, and sodomized at gunpoint; was released)
  • April 19, 1997, Indio, California: Anthony Michael Martinez, 10 (abducted on April 2 in Beaumont, California; molested and killed, allegedly by bludgeoning with a rock)
  • July 3, 2004, Detroit Lakes, Minnesota:
    • Unnamed six-year-old boy (molested only)
    • The boy's unnamed friend (attempted to molest)
  • 2005:
    • May 16, Coeur d'Alene, Idaho: The Groene family
      • The killings at the Groene house (all of the following were bludgeoned with a claw-hammer):
        • Brenda Groene, 40
        • Mark McKenzie, 37 (Brenda Groene's boyfriend)
        • Slade Groene, 13 (Brenda Groene's oldest son)
      • The double abduction:
        • Dylan Groene, 9 (Brenda Groene's youngest son; repeatedly raped, molested, and tortured; fatally shot and burned post-mortem; his body was found on July 4)
        • Shasta Groene, 8 (Brenda Groene's daughter; repeatedly raped and molested; was rescued on July 2)


  • March 31, 1997, Oak Harbor, Washington: Deborah Palmer, 7 (disappeared on March 27)
  • February 10, 1998, Bothell, Washington: Sammiejo White and Carmen Cubias (disappeared on July 6, 1996 in Seattle, Washington; confessed to their murders, but wasn't charged):
    • Sammiejo White, 11
    • Carmen Cubias, 9 (Sammiejo White's half-sister)
  • Unspecified dates in 2005: Possibly stalked the following:
    • Unnamed girl, 10
    • Her unnamed sister
    • Her sister's unnamed friend
  • Note: During his stay at Dyslin's Boys' ranch, Duncan once told a therapist that he had bound and sexually assaulted six boys, and also raped an estimated thirteen others.

On Criminal Minds[]

  • Season Eight
    • "Through the Looking Glass" - While not directly mentioned or referenced in this episode, Duncan appears to have been an inspiration for the episode's unsub, Arthur Rykov - Both are serial killers, family annihilators, stalkers, and abductors who had a habit of killing the parents and the oldest child before dumping them both together, yet dumping the youngest child elsewhere.
    • "The Apprenticeship" - Duncan was possibly mentioned alongside Thomas Dillon as an example of serial killers who don't start committing murders until they are middle-aged. However, the details the BAU provided of the named criminal do not match official details given on Duncan.
  • Season Eleven
    • "The Sandman" - While not directly mentioned or referenced in this episode, Duncan appears to have been an inspiration for the episode's unsub, Patrick Sorenson - Both were serial killers, family annihilators, and abductors who abducted children from their homes after killing the rest of the family, and, in one case, killed the sons they abducted before they could be saved.



  1. An abbreviation given by Shasta of his name: Joseph Edward Duncan the Third