Most of the long series in the record rest on years of arithmetic that nobody can check. The short ones rest on a calendar. A man who killed on a Sunday and again on the following Friday leaves a span that a reader can count on one hand, and the count is a different kind of evidence from a confession that stretches over thirty years. It is also a more fragile one: the shorter the span, the more depends on a single date, and several of the dates here are given differently by different sources.
The ten cases that follow run from about a week to about two months. Outlets call these cases a series, a spree or nothing at all.
Prosecutors in Tarrant County, Texas, told a jury that Jason Alan Thornburg killed three people over about seven days in September 2021 [1][2]. The Texas Department of Criminal Justice record dates the offense to September 21, 2021 [3]. The three were David Lueras, 42, Maricruz Mathis, 33, and Lauren Phillips, 34 [4][5]. Police said Thornburg knew them, two of them only casually [4]. He was arrested in late September 2021 and indicted on December 13 of that year on one count of capital murder covering all three [4][5][6].
On November 20, 2024, a Tarrant County jury rejected his insanity defense and convicted him of capital murder of multiple persons, and on December 4, 2024, he was sentenced to death [7][8][9]. His direct appeal was set for oral argument before the Texas Court of Criminal Appeals on October 14, 2026 [10]. No decision has been reported.
The week in September is the convicted span. The wider record is not. Police said Thornburg confessed to the May 2021 death of his roommate, Mark Jewell, 61, and a grand jury indicted him for murder and arson in that case on February 18, 2022; it has not been tried [11][12]. Police also said he confessed to the March 2017 death of his former girlfriend, Tanya Begay, 36, and the Associated Press reported that a federal grand jury in Arizona indicted him in 2022 over a death on the Navajo Nation, with no outcome reported [13][14][15][16]. The Associated Press headline of May 2022 speaks of a man who "admitted killing 5" [16]. If those confessions were ever proved, the span would run from March 2017 to September 2021, four and a half years. As things stand, three deaths in a week are convicted, one death in May 2021 is charged, and the 2017 death rests on what police say he told them.
CBS Texas called him a suspected serial killer from the day of his arrest [13]. The prosecutors' own phrase at trial was a matter of days. Nothing reconciles the label with the span.
Three Muslim men were killed in Albuquerque, New Mexico, in ten days in the summer of 2022: Aftab Hussein, 41, on July 26; Muhammad Afzaal Hussain, 27, on August 1; and Naeem Hussain, 25, on August 5 [17][18][19]. Those dates fix the span at ten days. A fourth killing, in November 2021, was something police raised in the first days of the investigation; they named Muhammad Syed the main suspect in it, and he was never charged with it [18][20].
The community lived those ten days and the days after with the fear that someone was hunting its men. The Associated Press reported that Albuquerque’s Muslim community numbered about 4,500 people and that many were afraid to go out [17]. The FBI formed a task force of more than 100 investigators and analysts, and rewards offered by various groups reached $30,000, according to the Albuquerque Journal [18]. President Joe Biden condemned the killings, and Governor Michelle Lujan Grisham said, "This is not who we are" [17].
The arrest came on the night of Monday, August 8, 2022, by the Associated Press’s account, or on August 9, according to later Albuquerque Journal reports [17][18]. Muhammad Syed, 51, an Afghan refugee admitted to the United States in 2016, worshipped at the same mosque as the dead men, and tips from within the community had led police to him [17][20]. At the news conference Police Chief Harold Medina said it was not yet clear whether the deaths should be classed as hate crimes, serial killings or both [18]. Syed denied any part [18].
He was indicted on three counts of first-degree murder and four of tampering with evidence [21]. A jury convicted him on March 18, 2024, of the first-degree murder of Aftab Hussein [22][23][24][25]. On September 3, 2024, he pleaded no contest to second-degree murder in the deaths of Muhammad Afzaal Hussain and Naeem Hussain, and the tampering counts were dropped [26][27]. On November 8, 2024, he was sentenced to life with at least 30 years to serve before parole eligibility, and the New Mexico Supreme Court upheld the murder conviction on May 7, 2026 [28][29][30]. No motive was established in court [29][26]. The ten-day span is therefore partly proved by a jury and partly by pleas that admit no facts, and the one verdict that went to trial concerns only the first of the three deaths.
Two girls died in Stockholm in the late summer of 1963, three weeks apart. Berit Margareta Glesing was six and died on August 12; Ann-Kristin Svensson was four and died on September 2 after being taken to hospital [31]. The dates give a span of 21 days. John Ingvar Löfgren, a 33-year-old gardener, was arrested in September and confessed to both killings [31]. The name was printed as Löfgren in 1963. The outcome of any court case against him has not been reported.
What the yearbook reports at length is the failure of the police. Five reports had been made about him before the second child died; only one had been registered, and he had not been classified as a suspect [31]. The most important tip had come from his own relatives and had never been followed up, and by the time detectives first saw it every document concerning him had gone missing and was recovered only after an intensive search [31]. The Stockholm police chief, Nils Lüning, asked for an impartial inquiry, which the parliamentary ombudsman gave to its head of department, Gösta Lidberg [31]. In three of ten questions put to the Stockholm governor’s office the ombudsman spoke of "negligence" in the handling of the reports about Löfgren, and at the end of 1963 decisions were not expected before early 1964 [31].
The yearbook treated the second death as the work of the same hand. Critics said the second child would not have died had the criminal police done their work after the first [31]. Nothing in the account suggests a longer series; the span is two deaths in three weeks, and the attention fell on what happened between them.
For three weeks in February and March 1996 the spa town of Merano, in the Italian province of South Tyrol, lived with deaths it could not explain. Two people died in the center of the town on February 8: Hans Otto Detmering, 61, a senior official of the German central bank who was on holiday, and Clorinda Cecchetti, 50 [32][33]. Umberto Marchioro, a farmhand, died on the edge of the town, and his death came to light on February 14 [34]. Paolo Vecchiolini, an accountant, died on February 27, and his fiancée survived [34][33]. On the morning of March 1, Tullio Melchiorri, a farmer, and Guerrino Botte, a carabinieri marshal, died at Rifiano, a village in the hills above the town [35][36].
Investigators attributed all six deaths to Ferdinand Gamper, a 39-year-old shepherd who had grown up in the Passeier valley [35][36][33]. He was never charged. He died by suicide on March 1, and no court has weighed the evidence [35][36][37]. The case investigators described in March 1996 rested on a firearm that the carabinieri said had been used in the first killings, on the fiancée’s description, and on notes in which he appeared to claim the deaths [35][36][38]. The span, from February 8 to March 1, is 22 days by the calendar, and L’Unità's own headline of February 16 asked "Serial killer a Merano?" with the question mark in place [34]. Twenty years later L’Adige used the words "serial killer" without the question [39].
One thing is well documented: a young local man was held as the suspect for 22 days, by L’Unità's count, and was released on the night of March 1 [38][40]. At Vecchiolini’s funeral on March 2 a priest told mourners, "They crucified an innocent man" [40]. Investigators set aside the first theories, one of a crime of passion tied to the couple, another of a professional hand, and a political reading of Gamper’s notes was rejected by the prosecutor Paul Ranzi, who reported no contact between Gamper and extremist groups [32][41][42]. Politicians on both sides of the language divide condemned the killings and argued over what they meant [42].
Tarfusser, later a judge at the International Criminal Court after serving as chief prosecutor in Bolzano, told L’Adige in 2016 that the pressure on the investigators was "truly enormous" and described an "extreme situation, rarely experienced in South Tyrol, before or since" [39][43]. The victims had no known links to one another, he said in 2021, which made the case extremely difficult [43].
The Durban newspaper the Daily News, in a 2011 feature, placed the murders of Bongani Mfeka in 1995 and called them a spree of about three weeks [44]. He pleaded guilty to four murders, with other charges, and received four life sentences; the paper said he confessed in detail [44]. The women who died were commuters in and around Kranskop, a village in the KwaZulu-Natal Midlands [44].
The court, the judge and the date of sentence have not been reported, and no dates within 1995 have been published. The three weeks rest on one newspaper’s description, and the word the paper chose was spree, not series. That makes it the thinnest span in the group: four life sentences, a year and a duration.
Igor Suprunyuk was 19 when he and two former classmates were arrested in Dnipropetrovsk, an industrial city in eastern Ukraine, on July 23, 2007 [45][46]. Within a day police said the young men had admitted to 19 killings in about a month; by the time of the trial the count had risen to 21 [45][46][47]. On February 11, 2009, the Court of Appeal of Dnipropetrovsk Oblast convicted Suprunyuk of 21 murders, 18 jointly with Viktor Sayenko and three alone, and sentenced him to life imprisonment with confiscation of property [48][49][50]. The Supreme Court of Ukraine upheld the sentence on November 24, 2009 [51][52]. The third young man, Oleksandr Hanzha, was convicted of robbery and served nine years [53][54].
The dates are where the sources disagree. Gazeta.ua reported that the first deaths came to light on June 26, 2007, and the main series ran from that day to July 19, three days before the arrests, a span of 23 days [46][52]. Prosecutors, however, charged that the series began on March 3, 2007, with the death of Viktor Hatuniak, 61, which would stretch it to nearly four and a half months [55][56]. Other accounts, Dnepr.info among them, put the first killing in late June, which is when the city became aware that something was wrong [51]. The count of dead also varies outside the court: 21 in the verdict, 22 in Strana and Telegraf, 23 in Radio Svoboda [50][53][56]. The verdict fixes 21 for the purposes of the record.
Police and prosecutors said the victims had nothing in common. "They were not interested either in age, or in social position," an official named Kupianskiy said in July 2007 [45]. Prosecutors said one victim was a 13-year-old child [46]. The court named a motive different from the greed that prosecutors had suggested: in the words reported from the verdict, a morbid or aggressive drive to assert themselves at any cost and to overcome their own fear [57][48][50]. The court described Suprunyuk and Sayenko as serial killers [50]. A forensic psychiatric examination judged all three young men sane [55].
Suprunyuk did not accept the verdict. He gave statements against himself after his arrest, then withdrew them and said he was innocent, as did Sayenko, and their families insisted for years that the investigation had been botched [47][58]. Radio Svoboda reported on the day of the verdict that prosecutors had opened three criminal cases against police officers for official negligence in the investigation [50]. A sister of one victim told a Dnipropetrovsk newspaper in 2008 that a man who reported being assaulted by Suprunyuk and Hanzha in Dniprodzerzhynsk had seen the two detained and then released, and that the killings went on afterward; that account was hers, and no court is known to have tested it [59][52].
Kimberly Clark Saenz, a licensed vocational nurse, worked at a dialysis clinic in Lufkin, in East Texas. The courts that reviewed her case set out the month in dates. On April 1, 2008, two patients, Clara Strange and Thelma Metcalf, went into cardiac arrest and died. On April 16 Garlin Kelley went into cardiac arrest; on April 22 Cora Bryant did; on April 26 Opal Few did and died. On April 28 two more patients had sudden drops in blood pressure [60][61][62]. Kelley and Bryant did not die at once: the 2014 opinion gives Kelley’s date of death as August 18, 2008, and Bryant’s as July 15, 2008, while the 2015 opinion says Kelley died two days after his collapse, so the opinions differ on his date [60][62]. The span in the opinions is April 1 to April 28, 2008, and the dates of death within it are three: April 1, April 26 and, for two patients, later in the summer.
On April 28, with state health inspectors in the clinic, two patients reported what they had seen a nurse do to two other patients, and that nurse was Saenz [63][64]. Lufkin police arrested her on May 30, 2008, on two counts of aggravated assault [60][63]. She was indicted in 2009 for capital murder and aggravated assault [65][66]. After a trial that opened in March 2012 [64][67], an Angelina County jury convicted her on March 30 of capital murder and three counts of aggravated assault, and acquitted her of two assault counts [68][69]. On April 2 the jury chose life without parole over death [69][70].
The capital murder count named all five patients in a single count, and the jury had to find that she caused the deaths of at least two of them [60][61]. That structure produced the appeal. The Court of Appeals affirmed on January 22, 2014; the Texas Court of Criminal Appeals identified a jury-charge error on December 10, 2014, and sent the case back, and the Court of Appeals affirmed again on August 26, 2015 [60][61][62]. The question at the center of the appeals was whether jurors who convict someone of killing more than one person must agree on which persons [60][61]. Her lawyers argued that she was a scapegoat for a badly run clinic [65][64]. The month of April 2008 is the convicted span, and the law required the jury to link two of five named patients to the one verdict.
David Birnie and his partner Catherine Birnie murdered four women in Perth, Western Australia, in October and November 1986, over about five weeks, according to ABC News [71]. ABC named the four in 2005 as Mary Nielson, 22; Susanna Candy, 15; Noelene Patterson, 31; and Denise Brown, 21, and noted that other published accounts spell the first two surnames and given names differently [71]. A fifth young person, a 17-year-old girl, survived, and it was her contact with the police in November 1986 that ended the series [71][72].
Both pleaded guilty, ABC News reported, and both received life sentences in 1987. In sentencing David Birnie, Justice Wallace said he should never be released [71][72]. The full list of counts on which he was sentenced, and the date of sentence, have not been reported [73].
David Birnie spent 19 years in prison. On October 7, 2005, aged 54, he died in his cell at Casuarina Prison, a maximum-security prison [71][72]. An inquest heard that he had gone three days without his antidepressant medication because of a paperwork error, and on June 18, 2008, the Deputy State Coroner, Evelyn Vicker, concluded that the missed medication contributed to his decision to take his own life, though she would not conclude that it caused his death [73][74]. He died by suicide, and no court ever examined any claim beyond the four murders. The Australian Associated Press reported in February 2017, after a Seven Network program, that he had allegedly alluded to three more killings between 1980 and 1986; these were claims and not findings, and no court has linked him to those women [75].
The case outlasted him in law. Catherine Birnie became the subject of a Western Australian statute: the Sentence Administration Amendment (Multiple Murderers) Bill 2018, introduced on October 18, 2018, let the Attorney-General direct that a prisoner convicted of serial killings, defined as two or more murders on separate days, not be considered for parole for up to six years at a time [76][77]. The ABC reported in November 2024 that the Attorney-General had directed that she not be considered for parole before December 13, 2030 [78].
Matthew James Harris killed three people with disabilities in Wagga Wagga, New South Wales, in late 1998. Peter Wennerbom was 62, Yvonne Ford 33 and Ron Galvin 53 [79][80]. Justice Virginia Bell of the Supreme Court of New South Wales said, in the words quoted in the Sapa-AFP report, that "in six weeks" he killed three people in separate incidents [79]. The Public Defenders' tables, which summarize the Court of Criminal Appeal’s reasons, put the three deaths within one month [81]. The two descriptions are both attributed to the courts, and they do not agree: six weeks from the sentencing judge, a month from the summary of the appeal court. Either way the span is brief.
He pleaded guilty to three counts of murder [79][80]. In 2000 Justice Bell declined to impose life imprisonment and gave him concurrent terms of 40 years with a 25-year non-parole period, finding that his deprived upbringing had played a part [79][82]. The brother of Yvonne Ford protested outside the court, and the Crown appealed; later in 2000 the Court of Criminal Appeal set the finite term aside and imposed life imprisonment [79][82][83]. The Public Defenders' table of natural life sentences for murder lists the appeal decision, R v Harris [2000] NSWCCA 469 [82].
The courts drew a line inside the span. The first death, as Justice Bell concluded, began as a robbery; the second and third, according to the summary of the appeal court’s reasoning, were motivated by a desire to kill [82][81]. The appeal court treated the later killings as encouraged by the success of the first [82]. In the Sapa-AFP account Harris told police that "to murder and get away with it was an achievement," and that he would have kept going had he not been caught [79]. Justice Bell nonetheless treated his admissions as significant in weighing sentence [79]. The Daily Advertiser of Wagga Wagga returned to the case in 2022 in the first season of a podcast, with Superintendent Rod Smith recalling the arrest [80].
Beverley Allitt was an enrolled nurse aged 22 on Ward 4, the children’s ward of Grantham and Kesteven General Hospital in Lincolnshire, in the spring of 1991. Thirteen children came to harm. Four died, three babies and an 11-year-old boy; nine survived, some with lasting injury [84][85]. On May 28, 1993, at Nottingham Crown Court, Mr. Justice Latham sentenced her to 13 life sentences, one for each child, after a jury convicted her of four counts of murder, three of attempted murder and six of causing grievous bodily harm with intent [86][84].
The span is the subject of three counts. The BMJ, reporting the Clothier inquiry in February 1994, said Allitt spent 58 days on the ward between February and April 1991 [87]. Local reports have given 59 days [88][89]. David Blunkett, then Labour’s health spokesman, told the Commons that there were 26 incidents involving 13 children over 61 days [90]. The inquiry itself did not make the span a finding; the three numbers come from a medical journal, a local paper and a politician, and they describe the same few weeks. The crash team from the Queen’s Medical Centre in Nottingham was called to the ward four times in about two and a half weeks, according to Blunkett [90].
Public reports describe an outline: children admitted with minor ailments collapsed, some stopped breathing, some went into cardiac arrest, and seven were transferred to Nottingham [90][85]. The Press Association summarized the later investigation by saying that the same nurse was on duty each time [84]. The first death came in February 1991 [85]. The inquiry treated it as a moment when the sequence might have been stopped: an attempt to arrange a pediatric pathologist’s examination was blocked, and the report suggested that a specialist examination might have brought what followed to a halt [87].
The central finding of the inquiry concerned time. A laboratory result showing that a baby had been harmed deliberately reached the hospital on April 12, 1991, the BMJ reported; the police were not called until April 30, and in between another child died [87][90]. The inquiry called the response in that interval "feeble and indecisive" [87], and the Health Secretary, Virginia Bottomley, told the Commons that the report drew attention to "the failure to take quicker action after the first evidence of possible foul play" [90]. The inquiry called hospital appointment procedures "sloppy" [87]. A regional inquiry in 1992 had made 51 recommendations, on all of which action had been taken by the time of the Clothier report, Bottomley said [90].
Allitt was arrested in November 1991, according to VICE [85]. Her minimum term of 30 years, fixed in 2007 and reduced by time in custody, expired in November 2021, the Grantham Journal reported; she was detained at Rampton Secure Hospital as of October 2023 and had sought a transfer to a prison [88]. The family of one survivor told the paper in 2021 that they feared for her safety should Allitt be released [89]. The BMJ’s own account of the inquiry’s report was headed with the words "serial killer" [87]; Thirlwall Inquiry material of 2024 returned to the Clothier lessons [91][92].
Put the ten spans on one line and the shape is plain: about a week for Thornburg, ten days for Syed, three weeks for Löfgren, Gamper and Mfeka, three and a half for the main series in Dnipropetrovsk, four for Saenz, five for the Birnies, six for Harris and eight for Allitt. The longer figures in some cases belong to prosecutors' broader dating (Suprunyuk, from March 3, 2007), to police statements about confessions (Thornburg, 2017 and May 2021) or to claims never tested (David Birnie, 1980 to 1986), and the short ones are the figures that courts or inquiries gave.
The labels do not line up with the spans. Newspapers reached for "serial killer" in Merano, Grantham and Albuquerque; in Merano the question mark was printed, and in Albuquerque the police chief declined to choose between hate crimes, serial killings or both. The Daily News called Kranskop a spree. The Dnipropetrovsk court itself used the words serial killers, and the Texas jury convicted on a single count of capital murder of multiple persons. Neither a court nor a newspaper in these cases offers a rule for how many deaths in how many days make a series.
• August 12, 1963: Berit Margareta Glesing, 6, dies in Stockholm [31].
• September 2, 1963: Ann-Kristin Svensson, 4, dies in Stockholm; John Ingvar Löfgren is arrested and confesses that month [31].
• End of 1963: The ombudsman’s inquiry into the police is still open [31].
• October and November 1986: The four Perth murders for which David and Catherine Birnie were convicted [71].
• 1987: The Birnies receive life sentences [71][72].
• February to April 1991: The Ward 4 period at Grantham [87].
• April 12, 1991: A laboratory result reaches the hospital; the police are called on April 30 [87].
• November 1991: Beverley Allitt arrested [85].
• May 28, 1993: Allitt sentenced to 13 life sentences [86].
• February 11, 1994: The Clothier report laid before Parliament [90].
• 1995: Bongani Mfeka’s spree of about three weeks [44].
• February 8 to March 1, 1996: Deaths in Merano and Rifiano attributed to Ferdinand Gamper, who died by suicide on March 1 [32][35][36].
• Late 1998: Matthew Harris’s three murders [79][81].
• 2000: Harris’s sentence of 40 years is replaced by life imprisonment [79][82].
• October 7, 2005: David Birnie dies in prison [71].
• March 3, 2007: Prosecutors' date for the first Dnipropetrovsk killing [55][56].
• June 26 to July 19, 2007: The main Dnipropetrovsk series [46][52].
• July 23, 2007: Suprunyuk and two former classmates arrested [45][46].
• April 2008: The Lufkin clinic period [60].
• February 11, 2009: Suprunyuk sentenced to life [48][49][50].
• March 30, 2012: Kimberly Saenz convicted of capital murder; April 2, life without parole [68][69].
• September 2021: The three deaths for which Jason Thornburg was convicted, over about seven days [1][2].
• July 26 to August 5, 2022: Three men killed in Albuquerque [17][18][19].
• March 18, 2024: Muhammad Syed convicted at trial of one murder [22][24].
• September 3, 2024: Syed’s no-contest pleas to two counts of second-degree murder [26][27].
• November 8, 2024: Syed sentenced [28].
• November 20 and December 4, 2024: Thornburg convicted and sentenced to death [7][8][9].
• May 7, 2026: New Mexico Supreme Court upholds Syed’s murder conviction [29][30].
• October 14, 2026: Thornburg’s appeal set for oral argument [10].