David Campbell exhibited a pattern of smug and arrogant behavior throughout his 15-day murder trial, a stark contrast to the grief of the victim's family. Campbell, 77, was on trial for the murder of Brian Low, 65, who was shot with a shotgun in rural Perthshire in February 2024. The incident occurred as Low was walking his dog near Aberfeldy, an area rarely experiencing violent crime.

Throughout the proceedings, Campbell was observed smiling, winking, and blowing kisses from the court dock, even displaying affection towards his wife when she testified. As footage of his police interview was shown, he was seen chuckling at his own remarks. This behavior persisted until the jury delivered a guilty verdict, at which point he displayed a look of astonishment.

The case is the subject of a new two-part documentary, "Murder Trial: Death of a Dog Walker," which chronicles the police investigation and judicial process. The investigation faced initial setbacks when a detective constable at the crime scene mistook the victim's wounds for injuries from a fall, failing to recognize the presence of numerous shotgun pellets. This oversight delayed the launch of a murder investigation by nearly a week, resulting in the loss of crucial days for forensic examination.

Pam Curran, Mr. Low's partner of 23 years, and his brother Douglas Low, have spoken publicly about the profound impact of his loss. Curran described the trial as "15 days of hell" and admitted to being too fearful to attend the verdict, waiting in a witness room. Douglas Low expressed disbelief and anger at the initial police assessment of his brother's death and was visibly distraught by graphic crime scene photographs.

Bad blood between Campbell and Low is believed to have stemmed from Low's criticism of Campbell's methods as a gamekeeper on the Edradynate Estate. Campbell had previously been investigated for wildlife crimes, including poisoning birds of prey. Prosecutors suggested Campbell blamed Low for his job loss, providing a motive for the murder. Curran confirmed she was aware of a serious dispute between them related to the wildlife investigations.

During the trial, cameras captured Campbell's remorseless demeanor in contrast to the visible distress of the victim's family. Footage from Campbell's own doorbell camera, which showed him covering the lens with tape on the day of the murder, was presented as evidence, despite his denial of leaving his home. Low's body was discovered the morning after he was believed to have been shot.

After three days of deliberation, the jury found Campbell guilty. He was subsequently sentenced to a minimum of 19 years in prison. The documentary highlights the emotional toll on Low's family and partner, with the judge recounting their victim impact statements expressing overwhelming grief and loss. As Campbell was led away after sentencing, he glanced at his family, but this time without blowing kisses.