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Fingerprint Evidence Leads to Murder Conviction and Execution (in 1920 New Zealand)

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These days when we think about forensic evidence our minds turn to shows such as the “CSI” franchise.  We think of DNA.  Bullet striations.  Hair and fiber analysis.  And fingerprints.  Of all these things, fingerprint matching has perhaps the longest history and remains one of the most used tools for identifying criminals.  I was therefore interested to learn recently that a New Zealand case, decided on this day, May 28, in 1920, was one of the very first in the world to result in a conviction for a capital crime based almost entirely on fingerprint evidence.  So, I did some digging.

The old Ponsonby Post Office, Auckland, New Zealand.  (Source: Flickr user Wonderferret, Dec. 3, 2007; used under Create Commons license.)
The old Ponsonby Post Office, Auckland, New Zealand, Dec. 3, 2007. (Source: Flickr user wonderferret; used under Create Commons license,

Dennis Gunn, 25 years old, was charged with the murder of Augustus Edward Braithwaite, who was the postmaster of Ponsonby, Auckland.  Mr. Braithwaite had been shot and killed in his home on the evening of March 13, 1920.  His keys were taken and used to access the strongroom at the post office, from which £67 14s. 5 d (67 pounds, 14 shillings and 5 pence) was stolen.   There were fingerprints on several cash boxes at the post office.  These boxes, along with a list of criminals who were in Auckland and who were thought to have possibly been involved in the crime, were taken by a detective to the Police Headquarters in Wellington on Sunday, March 15, where they were analyzed by specialists in the Criminal Registration Branch (CRB).  The trip from Auckland to Wellington took eighteen hours; today it is about an eight-hour drive.

Mr. Gunn’s name was not on the original list of possible suspects.  He was identified as a suspect on Monday, March 16, three days after the crime.  A former prison warden told police that he had seen Mr. Gunn in the vicinity of the post office on several occasions on the day of the murder.  This former prison warden knew who Mr. Gunn was because in 1918 he had worked in the prison where Mr. Gunn served a two-week sentence after being convicted of evading military service under the Military Service Act 1916.  As part of his arrest and conviction for that offense, Mr. Gunn’s fingerprints had been taken and stored.  Following the identification by the warden, Mr. Gunn’s name and that of another suspect were sent by telegram to the Police Headquarters, where the CRB analysts matched the fingerprints in his file with those on the cash boxes.  He was arrested the next day – just four days after the murder took place.

On March 20, the police found a recently-fired revolver in a gully near where Mr. Gunn lived, along with the keys and a large number of pennies.  The grooves on the revolver were found to match those on the bullets that had killed Mr. Braithwaite.  There was also a fingerprint on the revolver, so the same officer made another trip to Wellington to enable the CRB to identify that print.  It was found to match Mr. Gunn’s fingerprints in his file as well as those on the cash boxes.

The murder trial started on May 24, 1920, in the Auckland Supreme Court (now the Auckland High Court).  During the five-day trial Mr. Gunn’s lawyer argued “relentlessly” against the reliability of the fingerprint identification.  However, the jury accepted the fingerprint evidence as showing that Mr. Gunn had in fact been the killer, and convicted him of murder.  The defendant was sentenced to death and, following an unsuccessful application to the Cabinet for a reprieve, was hanged in Mount Eden Prison, Auckland, on June 22, 1920.  In his statement to the Government, Mr. Gunn admitted to being involved in the robbery, but contended that two other men had been involved in the murder and he had just been given the revolver after the fact.  The police investigated the whereabouts of these men on the evening of the crime and established that they had been elsewhere.

Auckland Supreme Court building, July 12, 2009. (Source: Flickr user russellstreet; used under Creative Commons license,
Auckland Supreme Court building, July 12, 2009. (Source: Flickr user russellstreet; used under Creative Commons license,

The case is identified as significant in New Zealand’s legal history because “the verdict finally disposed of all attempts in New Zealand to discredit the conclusiveness of fingerprint evidence in the detection of crime.”  A “Report of the Trial of Dennis Gunn for the Murder of Mr. Augustus Edward Braithwaite,” published in 1921 at the direction of the New Zealand Minister of Justice, is included in the “Making of Modern Laws: Trials, 1600-1926” publication.  This publication is available as an electronic resource in the Law Library’s Reading Room.  The report was prepared and published because the Minister of Justice “deemed it desirable to have an authentic report of the trial printed, as it is important to publish the evidence which a jury has held to prove conclusively the guilt of Dennis Gunn.”  The report includes the notes of evidence, covering all of the witnesses in the trial, that had been “taken down on a canopied typewriter” and handed to the judge sheet by sheet, which he then checked and adopted.  If you’re interested in criminal investigations, evidence rules, and trial procedure, as well as a bit of history, it actually makes for quite fascinating reading.

The case also merited a mention in the 1920 annual report of the “Police Force of the Dominion” (p. 5) that was presented to the New Zealand Parliament.  The report states that

The value of the finger-print system of identification has been shown during the year in several criminal cases, the most noteworthy being that of the murder of the Postmaster at Ponsonby, Auckland.  In this case finger-prints found on a cash-box in the Ponsonby Post-office, which had been broken into, were identified at the Criminal Registration Branch within twenty-four hours of receipt, and led to the arrest of the offender.  The finger-print evidence formed the principal link of the chain of circumstantial evidence upon which the accused was subsequently convicted of murder and executed.

This annual report, and those of other years, also provide statistics on the number of fingerprints in the Criminal Registration Branch’s collection each year since the introduction of the fingerprint system in March 1903, as well as the “number of prisoners traced as previous offenders” as a result of the system.  You can find such reports in the Appendix to the Journals of the House of Representatives, of which the years 1854 to 1950 have been digitized by the National Library of New Zealand and can be searched in the “AtoJsOnline” database.

There is also a quite detailed, and rather colorful, account of the trial in a 1933 edition of the New Zealand Railways Magazine, which is available online on the New Zealand Electronic Text Collection website maintained by the Victoria University of Wellington Library.  The article, titled “Famous New Zealand Trials – The Trial of Dennis Gunn” was written by Lieutenant Colonel Charles Archibald Lawrance Treadwell O.B.E., a soldier, author, and journalist who wrote a series of “Famous New Zealand Trials” articles in the 1930s.  The Law Library holds a compilation of these articles in our collection.

C.A.L. Treadwell, Notable New Zealand Trials (1936).
C.A.L. Treadwell, Notable New Zealand Trials (1936),

There was of course a fair amount of interest in the trial in the press around the country, as well as in Australia.  A search for “Dennis Gunn” in the National Library of New Zealand’sPapers Past” database resulted in 381 hits, including the following:

  • Murder Charge: Ponsonby Post Office Tragedy,” Dominion, Volume 13, Issue 205, 25 May 1920, Page 8.  This article included a transcript of part of the prosecutor’s opening statements in which he told the court that no two sets of fingerprints in the world are the same and that the case “really turns on the value of finger-print evidence.”
  • Fingerprint Evidence: An Expert’s Confidence,” Poverty Bay Herald, Volume XLVII, Issue 15227, 27 May 1920, Page 6.  This brief article highlighted the testimony of one Inspector Fowler, who had been in charge of the New South Wales police fingerprint bureau for 17 years and had also worked in this area at Scotland Yard.  The witness had independently analyzed the fingerprints in the case and testified that he was “more convinced that Gunn handled the revolver and the cashbox than if he had actual sight of him handling them.”  Information about Inspector Fowler’s testimony was also published in Australia.
  • The Evidence that Convicted Dennis Gunn,” Observer, Volume XL, Issue 40, 5 June 1920, Page 16.  This clipping is actually pictures of two fingerprints used as evidence in the case: a fingerprint taken from Mr. Gunn in 1918, and a fingerprint taken from inside one of the cash boxes.
  • Case of Dennis Gunn: Petition for Reprieve,” Evening Post, Volume XCIX, Issue 136, 9 June 1920, Page 7.  This article states that the petition was circulated and a meeting of a group of people who supported commutation of the sentence resulted in a resolution being sent to the Governor-General and Minister of Justice.
  • Condemned Man’s Story,” New Zealand Herald, Volume LVII, Issue 17504, 23 June 1920, Page 6.  This article reports on the Government’s statement regarding its consideration of Mr. Gunn’s application for a reprieve from the death sentence.  It states that “[t]here has never been a case of the kind that has given the Government so much concern.”
Mount Eden prison, Jan. 11, 2011.  (Source: Flickr user russellstreet; used under Creative Commons license,
Mount Eden prison, Jan. 11, 2011. (Source: Flickr user russellstreet; used under Creative Commons license,

More recently, in 2010, an article about the conviction and execution of Mr. Gunn was published on a New Zealand website.  It notes that his family “remained unconvinced” about his guilt, with his gravestone inscribed with the following words: “In Loving Memory of Dennis Gunn.  Sadly wronged.”  In fact, the gravestone and the story behind Mr. Gunn’s demise were featured on the New Zealand television show “Epitaph” in a 1999 episode titled “An Unforgettable Signature.”

I found several other interesting pieces of information linked to the Braithwaite murder case in my searches, including:

  • Biographies of Detective Sergeant James Cummings, who led the investigation and was commended by the judge for his efforts and fairness, as well as a detective who assisted with the investigation, John Bruce Young.  Apparently, the reputations of both men were significantly enhanced or solidified as a result of the investigation and conviction.  Cummings later became the police commissioner, succeeding his brother Denis.  (A small aside: Denis Cummings was at one time in charge of the Masterton police sub-district, my home town.)
  • A biography of a previous police commissioner, Walter Dinnie, who had worked for the London Metropolitan Police and had been “instrumental in setting up a new system of registering and identifying criminals based on fingerprinting” there in 1901.  After he was hired by the New Zealand government, he “implemented with zeal further reforms in the New Zealand Police Force, particularly the utilisation of new scientific and technological advances to aid in the identification of offenders,” including reorganizing the new fingerprint identification system.  Mr. Dinnie’s son, Edmund (Ted), became the head of the Criminal Registration Branch that his father established, and it was he who made the match between Mr. Gunn’s fingerprints and those on the items taken as evidence.
  • The Ponsonby post office was put up for sale in 2003 and again in 2013.  The media reports about the sale of the property stated that it had been the focus of a “dramatic murder case” that attracted international attention, and provided some information about the trial and conviction of Mr. Gunn.

The Library of Congress holds many resources on forensic science, including fingerprinting.  Jennifer Harbster over at “Inside Adamswrote a post a couple of years ago highlighting useful guides for conducting research on this subject.  There is even at least one personal link within the Library: Ellen Terrell, a business reference librarian who also writes for that blog, has a great-grandfather who “was a pioneer in dermatoglyphics (scientific study of fingerprints).”  Awesome!

Dennis Gunn trial - first page
The first and last pages of “The Trial of Dennis Gunn” in C.A.L. Treadwell, Notable New Zealand Trials (1936),

Dennis Gunn trial - last page


  1. Hi would like to say firstly that there were 3 revolvers not one that was found by the police and that Dennis Gunn did not act alone with the robbery there were 3 people and even tho his fingerprints were on all 3 of the revolvers he did not fired the revolver killing the post master in 1920.
    Dennis always stated that he was guilty of the robbery but not guilty of the murder of the post master. No other evidence was found or used and to convict someone with very little evidence even today is wrong. My family has suffered to long with this its time to dig deeper and clear my ancestors name once and for all.

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