Theresa Knorr killed two of her own daughters in the Sacramento area in the mid-1980s. Suesan Knorr was 17 when she died in July 1984, set on fire beside a mountain road near Squaw Valley after weeks of untreated illness. Sheila Sanders was 20 when she died in June 1985, shut inside a closet in the family's apartment without food or water. Each time, Knorr had two of her teenage sons help take the body, or the dying girl, into the Sierra Nevada. Neither young woman was reported missing, and for eight years they were known only as unidentified homicide victims in two neighboring mountain counties.
The case was solved because the youngest sister, Terry, kept telling the story. She said police, a lawyer and a therapist in Utah had all dismissed it. In October 1993, after watching the television program "America's Most Wanted," she tried again, and California detectives found that her account matched both unsolved cases. Within days her mother and both brothers were charged with murder. In 1995 Knorr pleaded guilty to two counts of first-degree murder in exchange for the removal of the death penalty, and she was sentenced to two consecutive life terms. She remains in a California prison.
Theresa Jimmie Cross was born in Sacramento in March 1946. Later accounts give the day as either March 12 or March 14; the California Department of Corrections and Rehabilitation (CDCR) listed her age as 80 in October 2026, consistent with a 1946 birth. Very little about her childhood appears in contemporary news reporting. The book-length accounts of the case, Dennis McDougal's Mother's Day and Wensley Clarkson's Whatever Mother Says..., both published in 1995, cover her upbringing in more detail.
She married young. Her first husband was Clifford Sanders, and their son Howard was born in 1963. In 1964, when she was 18 and pregnant with her second child, she shot Sanders dead with a hunting rifle. She said she had grabbed the gun to stop him from hitting her. She was tried for murder, and a jury acquitted her, finding that she had acted in self-defense. That verdict stands: in law the shooting was not a murder, and it does not count among her crimes. When the 1993 investigation began, the Los Angeles Times reported that the new allegations had led authorities to look again at the 1964 case, but no new charge was ever brought.
Her daughter Sheila Gay Sanders was born in 1965, after her father's death.
Theresa then married Robert Knorr, and they had four children in about four years: Suesan, William, Robert Jr., and finally a daughter named Theresa after her mother, known as Terry, born in 1970. Robert Knorr left in 1970. His former wife later went back to her maiden name, Cross, although she married at least twice more. A Placer County sheriff's inspector, Johnnie Smith, told the Associated Press in 1993 that those later marriages were not long-term relationships. The Los Angeles Times reported that she had been married five times in all.
For about 13 years she and the children lived in Orangevale, a suburb northeast of Sacramento. In 1983 they moved into a small two-bedroom apartment off Auburn Boulevard in Sacramento, in a run-down area known for street prostitution. Howard, the eldest son, apparently never lived there, detectives believed.
Investigators who reconstructed the family's life in 1993 described a home controlled by beatings, isolation and threats. Sheriff's Lt. Chal DeCecco said most of the children never went beyond the eighth grade, and that their mother seldom let them out of her sight when they were at home. A childhood friend of Suesan's told investigators that Suesan became frantic when her school bus ran late, because she knew she would be beaten for coming home late.
Neighbors on Auburn Boulevard later told the Associated Press that the apartment was dirty and smelled of urine, that the children seemed nervous, and that their mother was secretive and never used the front door. According to the sheriff's office, Knorr had some nursing experience and did not want her daughters to be thin; she was said to force-feed them. Terry later told detectives that one of her sisters had chipped front teeth from being force-fed, a detail that would help identify a body.
Authorities said the daughters bore the worst of the abuse. In a 2003 interview for the A&E documentary series "Cold Case Files," Terry said she believed her mother was jealous of Sheila and Suesan as they grew into young women. She described being beaten with a board and said the children learned to stay out of their mother's way. The sons were also drawn in: according to the authorities' account in 1993, their mother used them to carry out punishments and, later, to help dispose of their sisters.
At least once, the Los Angeles Times reported, Sacramento County child welfare officials were told about abuse in the family but apparently took no action. County officials said in 1993 that they could not discuss the case because such records were destroyed after five years.
Suesan Marline Knorr was born in 1966, the first child of Theresa's marriage to Robert Knorr. The record of her short life is thin, and most of what survives comes from her sister's memories and from investigators. Her childhood friend remembered her fear of being late home. In her last year she wanted to leave: according to the sheriff's account, she told her mother she wanted to move to Alaska. Terry later remembered the jewelry Suesan wore, an antique ring and earrings with small bells, and described them to detectives without being asked.
During an argument at home, Knorr shot Suesan with a small-caliber handgun. The date varies between accounts. The sheriff placed it in 1983, when Suesan was about 16; Terry's account, as reported by the Associated Press, placed it perhaps as early as 1982. The bullet entered her chest and lodged in her back. She received no medical care, and to her family's surprise she recovered.
About a year later, when Suesan said she wanted to leave home, her mother agreed on one condition: the bullet had to come out first. Investigators said Knorr feared that the bullet could prove the shooting if Suesan ever reported the abuse. With liquor given as an anesthetic, the bullet was cut out on the kitchen floor. Accounts differ on who did the cutting and with what. The sheriff and Terry's 1993 statements said Knorr did it herself, with a kitchen knife or a scalpel; the publisher's description of McDougal's book says Knorr ordered one of her sons to remove it.
The wound became infected. Suesan grew weaker, then jaundiced and delirious. Rather than take her to a hospital, her mother decided, in the words of the court papers filed in 1993, that she would not recover and would have to be killed.
Knorr had her sons William and Robert help load Suesan into the car with her belongings. William was 16 at the time and Robert 15. The first attempt failed when the car broke down on Interstate 80 and they returned to Sacramento for repairs. The next night they drove about 100 miles into the Sierra Nevada and turned off the highway near the Squaw Valley ski area, stopping by Squaw Creek about half a mile from the resort entrance.
There, according to the sheriff's account, Suesan was laid on a pile of her own clothes and bags with her mouth taped, doused with gasoline and set on fire. The coroner later found that she had been alive when the fire was set. Her body was found the next morning, July 17, 1984, still smoldering. The fire had made identification impossible by sight, and she had no dental work to compare. She was recorded as an unidentified homicide victim, and Placer County's investigation went cold.
Sheila Gay Sanders was the eldest daughter, born in 1965, the child of Theresa's first marriage. By 1985 she was 20. Terry later said their mother had forced both older daughters into prostitution to bring money into the household; the prosecutor in 1995 described both daughters as victims of years of abuse. Little else about Sheila as a person appears in the public record that survives online, and the books remain the fullest accounts of her life.
In 1985, court documents said, Knorr accused Sheila of having caught a venereal disease. After a violent argument Sheila was beaten, bound (the documents describe strips of torn bed sheet; Terry's account mentions handcuffs) and locked in a narrow linen closet, which the sheriff described as about two feet square. Knorr told the rest of the family not to feed her. Terry, who was about 13 or 14, later told detectives that she heard her half-sister calling for help and that she once slipped her a can of beer. No one opened the door. Sheila died within several days.
Once the smell of decay filled the apartment, Knorr again called on her sons. According to Terry, William brought home a large cardboard box from the movie theater where he worked, marked as having held popcorn or drink cups. Sheila's body was put in the box and taped shut, and the family drove it into the mountains along Interstate 80. The box was left near Martis Creek, close to the Truckee-Tahoe airport in Nevada County, where a fisherman found it on June 21, 1985. Sheila could not be identified and joined her sister on the list of unnamed homicide victims, in a different county.
The smell did not leave the apartment. According to the sheriff, Knorr ordered Terry, then a teenager, to set the apartment on fire to destroy the evidence. In the night Terry spread barbecue lighter fluid around the rooms and lit it. The fire department came so quickly that the blaze did little damage and never reached the closet where Sheila had died; the building's other apartments were spared.
The family scattered afterward. Terry stayed with her mother for about three years and then ran away at 16, she said. Robert told detectives in 1993 that he had last seen his mother about six years earlier, in Reno, Nevada. Robert later moved to Las Vegas, where he was convicted of second-degree murder over the killing of a man during a 1992 robbery at a tavern; he was serving a 15-year sentence in Nevada when the Knorr case broke. William married and settled in the Sacramento area. Knorr herself eventually moved to Salt Lake City.
Terry also ended up in Utah, in the suburb of Sandy, where in 1993 she was working as a grocery store clerk in the same Salt Lake City neighborhood where her mother lived and worked. Reporters could not establish whether either knew the other was nearby.
Terry later said she had tried to report her sisters' deaths for years. She told the Associated Press that she began in 1987, going to a lawyer and to two police departments in Utah. A Sandy police detective, David Lundberg, told the Los Angeles Times that she had tried to report the killings to Utah police in 1989 and was not believed, and that a therapist also failed to take her seriously. No Utah agency publicly acknowledged turning her away. Inspector Smith said the only explanation investigators could offer was that the people she told found the story too strange to be true. Placer County Sheriff Donald J. Nunes said the case would have been solved much sooner if anyone had listened, because her descriptions were detailed enough that a routine computer check should have turned up the unidentified bodies.
Her own life was difficult. She had left home as a teenager, and in 1993 the Sandy detective said police had been called to her home repeatedly over domestic disputes. The A&E program later said she had a criminal record and problems with drugs and alcohol, which helped explain why she was not believed.
In October 1993, while watching "America's Most Wanted," Terry realized that charges could still be brought. Accounts of what happened next differ slightly. The sheriff's office said she looked at a map to see which agency had jurisdiction over the places where her sisters' bodies had been left, and then called the Placer County Sheriff's Department. In the A&E documentary, Terry said she first called the program's tip line, and a Nevada County sergeant, Ron Perea, said he took her call and passed it to Placer County, whose investigator, John Fitzgerald, recognized the burned body she described as an unsolved case. "She didn't want her mother to get away with any of this, and she wanted to tell her story," Detective Lundberg said.
Detectives had no tissue samples or dental records that could prove the victims' identities directly, so they tested Terry's account against the old case files. It matched point after point. The autopsy of the burned body had recorded a long wound in the back, where Terry said the bullet had been cut out; the Los Angeles Times reported that the coroner had found what were described as stab wounds in the back. Items found at the scene in 1984 fit her description of how Suesan had been kept while she was ill. She described the ring and earrings. For the second case, she knew the body had gone into a box from a movie theater, and the box in Nevada County had indeed held cups of the kind sold at theaters. Sheila's front teeth were broken, as Terry said they had been during force-feeding.
The sheriff's office said Terry's story was supported by statements from her brothers and by physical evidence found with the bodies. In the A&E documentary, detectives said fingerprints from bags at the 1984 scene matched Robert. Detectives also served a search warrant on the old Auburn Boulevard apartment, by then home to other tenants, and removed the stained subfloor of the closet for testing. Terry was not charged; Inspector Smith said there were no plans to charge her.
The arrests came quickly. William Knorr, then 26, was arrested on November 4, 1993, at the warehouse where he worked in Woodland, California. Robert Knorr, 24, was found in a Nevada prison and charged there. In a recorded interview played in the A&E documentary, William described the drive with Suesan into the mountains and said his mother poured the gasoline; asked why he had not walked away and called the police, he said she would have done what she threatened.
Before her mother's arrest, Terry told her story on KUTV in Salt Lake City. "What kind of mother would do that?" she asked. "What kind of person am I going to be for the rest of my life because of this?" Shortly before she was arrested, Detective Lundberg said, Theresa Knorr withdrew $4,000 from her bank account and told her employer she was leaving town. Placer County detectives traced her by checking her aliases against driver's license records around the country.
On Wednesday, November 10, 1993, she was arrested in Salt Lake City. She was 47 and was using the name Theresa Cross. She had been living in the home of an elderly woman (85 or 86, by different accounts) and caring for her around the clock for about 15 months. The woman's son, Bud Sullivan, told reporters he could not say anything bad about her and that the family had come to regard her as one of their own. Sheriff Nunes said he had served 33 years and had never seen a case like it.
Placer County filed two counts of murder against the mother and each son, and the case against Theresa Knorr was set out as two counts of first-degree murder and two counts of conspiracy to commit murder. The charges included special-circumstance allegations, which under California law made a death sentence possible; the Associated Press described the defendants as accused of "multiple murder and conspiracy."
On Monday, November 15, 1993, Knorr appeared by video from the Salt Lake County jail before Third Circuit Judge Michael Hutchings, said she could not afford a lawyer, and was given a public defender on a fugitive charge. She fought extradition for more than a month. At a hearing in December she told the court she did not believe she had been in California when the killings happened; a Utah prosecutor, Bud Ellett, answered that this was not a question for Utah courts, which had only to decide whether California was entitled to her and whether she was the right person. On December 17, 1993, Third District Judge Timothy Hanson rejected her challenge, and Placer County detectives took her back to California. Her Utah lawyer said the delay had let publicity in California die down and given time for California counsel to be appointed.
In June 1994 a Placer County municipal judge, Joseph O'Flaherty, postponed the preliminary hearing for Knorr and William to August at the prosecution's request, while Placer County waited for Robert to be brought from Nevada. A Nevada judge rejected Robert's challenge, which argued that he should not be prosecuted in California as an adult and that Placer County lacked jurisdiction because the crimes had been committed in Sacramento County.
The jurisdiction point carried weight. The prosecution was transferred to Sacramento County, where the events leading up to both deaths had taken place, and Sacramento County Deputy District Attorney John O'Mara took over. By November 1994 a trial for Knorr and William was set for February 1995 in Sacramento Superior Court, and O'Mara was negotiating a plea agreement with Robert's lawyer. Based on Terry's statements, detectives believed Robert's role had been minimal. Howard Sanders, the eldest son, and Terry were expected to testify about their childhood.
Robert's agreement changed the case. He pleaded guilty to being an accessory after the fact, and was in a position to testify against his mother. Knorr, who had pleaded not guilty, then pleaded guilty to both murders, and the death penalty was no longer sought, the Associated Press reported in August 1995.
At a hearing in Sacramento Superior Court in early August 1995 (the Associated Press report, published August 6, dates it to the preceding Tuesday), O'Mara outlined the agreement and a judge accepted that the death penalty would be off the table. Knorr, then 49, pleaded guilty to two counts of first-degree murder for the deaths of Suesan Marline Knorr in 1984 and Sheila Gay Sanders in 1985. She rocked on her feet as O'Mara recited the facts. Asked whether she was pleading guilty because she was in fact guilty, she hesitated before answering that she believed she would be found guilty. O'Mara told the court both daughters had suffered abuse over many years. Robert Knorr Sr., the father of four of her children including Suesan, cried out "No!" when the agreement was announced.
She was sentenced in October 1995 to two consecutive life terms. CDCR records show she was received into state prison on October 24, 1995. Because she is eligible for parole hearings, her sentence is one of life with the possibility of parole, not life without parole.
The legal outcomes for the brothers were very different from their mother's. Both had been minors at the time: William was 16 and 17, and Robert 15 and 16. Robert pleaded guilty to being an accessory after the fact to murder. A 2016 federal press release identifies Robert W. Knorr Jr. as having prior convictions for murder, with a 15-year sentence, and for accessory to murder after the fact, with a three-year sentence. That release reported that Robert W. Knorr Jr., then 47 and living in St. Joseph, Missouri, was sentenced on August 30, 2016, to eight years and one month in federal prison for a child pornography offense.
In August 1995 William still faced the murder charges and was due for a preliminary hearing before Sacramento Municipal Judge Renard F. Shepard. What became of those charges is not clear from the record.
Knorr is held at the California Institution for Women in Chino. California's elderly parole program made her eligible for parole consideration once she had served at least 20 continuous years and reached 50, or 25 years and reached 60; CDCR lists her parole-eligible date as January 2021, and notes that it can change.
Her first parole suitability hearing was scheduled for January 17, 2019, and postponed. At the hearing on July 3, 2019, the Board of Parole Hearings denied parole for five years. When she became due again, she waived her right to a hearing for one year on March 12, 2024, again on February 17, 2025, and again on June 30, 2026. As of October 16, 2026, CDCR showed her at the California Institution for Women, age 80, with a parole suitability hearing tentatively set for June 2027. No news coverage of the 2019 decision or of any later hearing was found.
The detectives who worked the case in 1993 spoke of how much it weighed on them. Lt. DeCecco said one officer asked him how the abuse could have gone on so long without anyone calling for help; DeCecco said he had to remind the officer that he was not dealing with normal people.
Terry said in 1993 that she wanted to rebury her sisters with their names on their headstones, and that whatever peace that brought them, there would be none for her. A decade later, in the A&E documentary, she said she had wanted her mother to answer for what she had done, and that more than anything she had wanted her sisters to have their names back. "They were somebody," she said. "And they were loved."
Two books appeared in 1995: Mother's Day by the journalist Dennis McDougal and Whatever Mother Says... by Wensley Clarkson. The case was the subject of the "Cold Case Files" episode "Mommy's Rules," which included Terry's interview, and of later true-crime television episodes.
Proven by her guilty pleas, and final: the first-degree murders of Suesan Knorr and Sheila Sanders.
Acquittal, not a murder: the 1964 shooting of Clifford Sanders. A jury found she acted in self-defense. Accounts written after 1993 that call it a murder are wrong in law.
Not charged: the 1983 strangling of her sister, Rosemary Norris, 39, whose body was left in Placer County. The sheriff's office reopened that case in 1993 because of the new allegations. No charge was ever brought against her, and nothing in the reporting links her to it.
Who fired the shot that wounded Suesan: the sheriff's 1993 account, Terry's 1993 statements and the 1993 court documents all say Knorr shot her. A later account attributed to Knorr herself, reported only in secondary sources, blames Terry; nothing in the record supports that.
Who removed the bullet, and with what: Knorr herself, with a kitchen knife (sheriff) or a scalpel (Terry, 1993), or a son acting on her order (later accounts, including the description of McDougal's book).
Details that vary between sources: the year of the shooting (1982 or 1983); how Sheila was restrained (strips of bed sheet, or handcuffs); whether Knorr went on the drive with Sheila's body; Terry's age in 1993 (22 or 23) and the year she first tried to report the killings (1987 or 1989); the age of the woman Knorr cared for in Salt Lake City (85 or 86; one 1995 report says an elderly man); the number of Knorr's marriages (four or five); and the spelling of the place where Sheila was found (Martis Creek, spelled Mardis in one wire report). Terry's later surname is given as Groves in 1994 and 1995 wire reports and as Graves in a publisher's description; the A&E program used Knorr Walker.
The plea date: the contemporary Associated Press report puts her guilty plea at a hearing in early August 1995. October 1995 is the date of her sentencing, not of the plea.
William Knorr's final outcome: how the murder charges against him were resolved is not known.
March 1946: Theresa Jimmie Cross is born in Sacramento, California.
1963: her son Howard is born to her and her first husband, Clifford Sanders.
1964: she shoots Clifford Sanders dead with a rifle; a jury acquits her on the ground of self-defense.
1965: Sheila Gay Sanders is born.
Late 1960s: Theresa marries Robert Knorr; Suesan (1966), William, Robert Jr. and Terry (1970) are born.
1970: Robert Knorr leaves the marriage.
About 1970 to 1983: the family lives in Orangevale.
1983: the family moves to an apartment off Auburn Boulevard, Sacramento.
1982 or 1983: Knorr shoots Suesan during an argument; she recovers without medical care.
1983: Knorr's sister, Rosemary Norris, is found strangled in Placer County (unsolved; Knorr never charged).
July 1984: the bullet is cut out at home; Suesan becomes gravely ill.
July 17, 1984: Suesan's body is found by Squaw Creek near Squaw Valley, Placer County; she is not identified.
June 1985: Sheila dies after being locked in a closet in the apartment.
June 21, 1985: Sheila's body is found in a box near Martis Creek, Nevada County; she is not identified.
1986: Terry sets fire to the apartment on her mother's orders; the closet is not damaged.
1987 to 1989: Terry tries to report the killings in Utah and is not believed.
1992: Robert Knorr Jr. is involved in a fatal Las Vegas tavern robbery; later serves 15 years in Nevada for second-degree murder.
October 1993: after watching "America's Most Wanted," Terry contacts California investigators.
November 4, 1993: William Knorr is arrested in Woodland, California.
November 10, 1993: Theresa Knorr is arrested in Salt Lake City.
November 15, 1993: Knorr is arraigned in Utah as a fugitive; California charges of murder and conspiracy are reported.
December 17, 1993: a Utah judge rejects her extradition challenge; she is returned to California.
June 1994: Placer County preliminary hearing postponed.
Late 1994: prosecution moved to Sacramento County.
1995: Robert Knorr Jr. pleads guilty to being an accessory after the fact.
Early August 1995: Theresa Knorr pleads guilty to two counts of first-degree murder; the death penalty is removed.
October 1995: sentenced to two consecutive life terms.
October 24, 1995: received into the state prison system.
1995: books by Dennis McDougal and Wensley Clarkson are published.
2003: A&E "Cold Case Files" episode with Terry's interview.
August 30, 2016: Robert W. Knorr Jr. sentenced in federal court in Missouri on an unrelated child pornography charge.
July 3, 2019: parole denied for five years.
March 12, 2024; February 17, 2025; June 30, 2026: Knorr waives parole hearings for one year each time.
October 16, 2026: in the California Institution for Women, age 80; next parole hearing tentatively June 2027.